I'll tell you for sure - SiRF III is superior and just plain amazing. No doubt about that. I'm using mapless GPS navigation units in tandem with PC and PDA mapping software primarily in the car for the past 7 years. Quite often we're traveling to the same camping/lodging places by the same routes. So I know exactly the dead spots on these routes where my old GPS (simple yellow eTrex) can't catch enough satellites to pinpoint my position. I have them marked on the map. I've found the best place in the car for my old GPS unit, where it's working best (under the sunroof). And almost bought an external amplified repeater antenna for it...

About 18 month ago I've got the SiRF III based GPS unit. And started using it in parallel with the old one. 10 of 12 dead spots just disappeared from my map. And I'm not anymore concerned about the new unit position in the car. It works fine even in the glovebox! Usually it's just sitting in my shirt pocket all the time (it's tiny and Bluetooth connected). Our most visited urban maze is San-Francisco. My old GPS was not reliable at all near the downtown. The new one works just fine!

And that's just simplistic Holux GPSlim-240.

I'm still quite content with a $15 compass and map. My dad just gave me his hand-me-down car GPS unit. I don't have the heart to tell him that it looks very pretty sitting in its box.

I use a dashboard mountable Garmin GPS V and it's plenty for me on the highway. The unit is for driving and one of the options is for the unit to be biased to a road (assume it's on a road) which gives it an additional piece of info. Setting it up as off-road works, but not as well. Usually though I'm using it as an ETA and mileage calculator. I know I'm on I-5, how far 'til my next gas stop and when will I get there. It does those calculations much better (more accurately) than I can and it's continually updating.

My primary GPS for hiking is a non-mapping and very small Garmin Geko 301. I use it for marking my car's parking spot, landmarks on the trail and (more importantly) major landmarks locations off the map. Preflight includes getting the GPS and map on the same page. GPS batteries last a long time when you only use it for the occasional fix and otherwise leave it off.

Neither unit has SiRF technology, not really needed for what I do.

Yep, I have both GPS Map 60 and a 60cx, the former with the old SiRF and the latter with SiRF III. It's much better at picking up signals in poor conditions. The newer unit can be carried in a rucksack or bag and still work; the older one couldn't so I had to wear it around my neck. Even then it was shielded by my body.

I don't think there's much difference in accuracy, though. The new one usually claims around 12-15ft. It's enabled for WAAS/EGNOS but in practice I rarely get a signal from those satellites where I live.

There may be a difference in acquisition speed but it's pretty nominal if both have good signals. The newer model does show satellite IDs almost immediately (which I think means it has recognised their signature and so has the right frequency and phase), but then you have to wait for the ephemeris to download, which can still take a minute or so. It's mostly luck how long it takes, depending on where in the cycle the broadcast is when you switch it on. Time to first lock is longer if the device is moving or if it's not been used for a few months, which may affect naive comparisons.

The extra sensitivity is a huge improvement regardless. As is having upgradable memory (I have a 2 Gig chip with topographic maps for my entire country) and various other changes.

I have to gloat a little. Up until about a year ago I worked for the automotive electronics part of Motorola - they made engine controlers, braking systems, telematics units (one of them is the OnStar unit), and, in relation to the telematics business they made their own GPS chipset. As a sort of internal consultant I did a lot of work with the telematics and GPS guys.

Well, it wasn't until recently that I found out that the GPS guys were sold to a company named ... SiRF. Cool, the chipset that is in the GPSMAP 60CSx that so impressed me is designed/made by people that I used to worked with. Its a small small world.

By the way, last Saturday I pulled out my old Garmin GPS III+ for the first time in a long time and turned it on (I was thinking of letting my son take it to Scout summer camp - but decided not to). While outside in a clear field it took no less than five loooong minutes to get a 3D lock. In the first minute it saw only one satellite straight overhead. Eventually it found four others with decent signal, but it took a long time. That just reaffirmed how amazing the SiRF GPS chipset is. Even when we went out to Glacier National Park and turned it on in a new location, the 60CSx took well under one minute to get a 3D lock. Amazing. AFter that the lock came in under 30 seconds.

Another thumbs up for the Garmin 60Cx here. Recently I upgraded to that model instead of the 60CSx because I have no use for a barometric pressure sensor or an electronic compass.

My previous GPS was a Garmin Legend. Prior to that I had a Garmin Venture. And have used a basic eTrex at work regularly.

With lots of tree cover and canyons in my area my poor Legend used to lose satellite lock quite a bit. Fast forward to the 60Cx... I am VERY impressed! It seems that almost as soon as you turn it on you are getting a good lock.

I have been using it for about four months now and I'll never go back. SIRF rocks!

Do the Garmin 60Cx and 60CSx have the same SiRF chip set?

Yes, the 60Cx and 60CSx have the same chip set - as do the 76Cx and the 76CSx.

[Oops, KenK beat me to it!]

Yes, I believe they are identical except for:

60Cx - color mapping (C), memory chip slot (x), SIRF.
60CSx - color mapping (C), sensor package (S)[elec. compass & baro. pressure], memory chip slot (x), SIRF.

I've read that the 60CSx can be a pain sometimes because you have to calibrate the electronic compass and barometric pressure sensor constantly. Also, I believe there is no way to disable the barometric pressure, so it's constantly running and draining the batteries a little more; in addition you can't see the GPS altitude, only your pressure altitude.

But that's just from some reading, I have not personally used a 60CSx. After four months of the 60Cx I don't have any desire for either of those bells or whistles.

A couple of web sites, www.gpsinformation.net and www.geocaching.com have some great info on GPS units.

Those new "H" series eTrex units with the high-sensitivity receiver chip look pretty sweet. I was wondering how long until Garmin updated them...

I've got the Geko 301 and it has the same baro altimeter and compass. The compass is the big battery drain so never turn it on. The baro altimeter seems to work pretty good though. I thought that the unit compared the baro and GPS altitudes. Need to check that; regardless it seems pretty accurate in elevation.