I have an 18" and a 24" version of the Trail Blazer buck saw.
They pack as a single aluminum tube with everything inside, Very nice. They assemble into an effective saw very quickly.
The only problem I have had is they have a spring that acts as a pin to hold them together when packed and people seem to lose them.

I like the saws with the bow frame too but they are a bit more awkward to stow.
I used to just take the blade and a couple of nails with me sometimes.
If you have the blade you can make a frame for it.

I think the best blades you can get today are Sandvik.
I have had blades by other brands that were bad. A few years ago some blades I got from Stanley Tools were supposed to be hard point, but they were soft like butter.

I found the triangular framed saws were not quite as good as the bow saws or the square frame buck saws because the frame limited the cut.

In a lot of the hardware stores you can find small 12" bow saws now.
They come with a swede saw blade and a hacksaw blade.
Very very handy.
You get a fast and aggressive wood saw and a very determined hacksaw all in one small package.
Again, I recommend the Sandvik brand for these little bow saws. The quality is high enough to be worth paying a little bit more.
Some of the imitations have poor steel in the blades and in the frames.