I was playing v1 probably 15 years ago, or more. After more than a decade, I got v2.2 and started playing about a two years ago. In my opinion v1 was a too slow to play - vehicle combat is tough to resolve and very time consuming, and the initiative system requires a lot of thought (though I did like it in principle).
v2.2 is one of my favourite game systems for balance between speed and complexity. I've got houserules for autofire and a few other things, but mostly I play it as is. I do prefer the v1 timeline except that it's a bit out of date now (we actually use a combination of the 2 timelines, and in fact it really makes little difference once you start playing). I also really like the v2.2 character generation system.
I agree that personal combat is not lethal enough in v2.2. To get around this I've done a few things, but the most significant is reducing "hit points" roughly to 2/3 of the original number (e.g. CONx2 = STR rather than 2x(CON + STR) for chest). I think v2.2 also makes it too easy to heal, so I've used what I think is v1 healing.
At the end of the day I wouldn't play v1 simply because of the vehicle combat system. I grew up on Warhammer Fantasy Roleplay and therefore started in d100, but I prefer the d20 system of v2.2 (it's not d20 d20, it just uses 20-sided dice). I like it because you can just pick up a bunch of d20s and roll them if you shoot multiple bullets rather than having to roll multiple d100s, which is quicker. v1 actually has a strange abstract system for smallarms which bugs some people too (each "shot" is actually 3 bullets - this is probably why it's more "lethal"). v2.2 has a cool quick-kill rule for head and chest shots that I like because it means that even low damage pistol rounds can you kill you out-right and this puts fear into every combat.
In short, I prefer v2.2because it's more streamlined but still very detailed. I play it as is except a few house rules:
- some weapons stats have been changed - just because I wanted to
- medical treatment rules have been slightly tweaked
- smallarms is tied to AGL not STR - recoil is still STR, however
- "Hit points" reduced
- Initiative system made a hybrid of v1 and v2.2 and the macro combat from ruins of warsaw (some suppression/morale rules also from tw2013)
- autofire at less than 1/2 of short range is at 1/2 skill and not 1/4. 5-round burst range increment also changed to S-5, M-3, L-2, E-1 because the rules as is had long range with 1-dice, which was a bit harsh.