I am confused. The Garmin page for the Vista HCx does not list it as a sirf-enabled unit. But the original poster describes the performance in ways similar to a sirf-enabled GPS.

Does the Vista HCx actually have sirf, or has Garmin developed some new technology that achieves sirf results? It certainly isn't WAAS that enables this new GPS to get great reception in traditionally difficult environments.

I'm not sure what kinda of chip set it has, but it's been working awesome. I had bought me this key chain FOB at CVS to store the Extra Map Micro SD cards in. I have had very fast acquisition time on it and have used it in some hard to get signal areas, what ever chip they used it works really really good.

http://www.cvs.com/CVSApp/cvs/gateway/detail?prodid=407151&previousURI=/CVSApp/cvs/gateway/search?page=2^Query=pill^ActiveCat=65^startLink=1

Sorry everyone, I posted my question before doing adequate research. The chipset on this GPS is a new one, not a sirf. In a nutshell, it achieves sirf-level performance while using less power. According to the GPS-philes on the various forums this new Garmin chipset is proving to be performing well and fulfilling the hype generated.

I'll be shopping for one soon.

FWIW, I re-read my posts and I noticed I didn't make myself completely clear. I did test lithium primary cells in my 60CSx with up to date firmware and the unit would power itself down. The 60CSx I have does *not* work with lithiums.

I'm really disappointed and don't understand their decision. A backpacking GPS should take lithiums!

-john

The point to Lithium is more than shelf-life - Alkeline cells perform poorly in cold temperatures. Lithium would be much preferred in very cold (well below freezing) weather.

I've never seen a datasheet on the Eneloop batteries and I don't know how they perform at low temperatures.

Some of Garmin's units use (internal) Lithium-ion batteries, and I assume many aspects of Garmin's products are shared (i.e., you do as much of the engineering as possible once to fit the entire product line and then customize for each individual product at the end - each product is not a clean-sheet effort). So parts of the design probably are intended to work with Lithium-ion, but not all, and it slipped through the cracks.

Garmin's reply on the Lithium issue sounds to me like a weasel-way of saying they screwed up. Someone forgot to actually *test* it before shipping.

I think that the limiting factor in cold weather is often the temperature sensitivity of the LCD screen, not the batteries. Keeping the GPS unit near your body will help with that, but then you'll have trouble with satellite acquisition.

And don't forget they are quite a bit lighter. When you add up the weights for the batteries in the devices and spares, it adds up!

And of course, lithium batteries outperform alkaline batteries quite a bit in most situations even in nominal temperatures.

-john

If it is cold enough for LCD screens to be affected, alkaline batteries are going to perform poorly to say the least.

-john

As I said earlier, if you run them down a bit first they will probably start to work. Their voltage is too high when they are new.