So I'm currently on Chapter 3 and the game is really kick-ass. The graphics are awesome, boss battles are HUGE, fantastic sound effects, excellent physics etc. However, I'd still vote for the first Resistance over this. Why? Here's why:
1.) This game only allows us to carry 2 weapons at a time, whereas the first one had an awesome grid system which stored all the weapons and switch them on the fly.
2.) Controls have changed a bit in Resistance 2. Melee attack is R3 now, you can sprint using L2 and also crouch use R2. They switched the Fareye sniper time slow down to R2, which is ridiculous.
3.) Is there no enemy info in the menu diary? Resistance 1 had neatly detailed everything in the journal.
4.) Bullseye's reload is slow in Resistance 2, whereas in Resistance: FOM, it would reload before you could even say "RELOADING"
5.) Less creepy environments and even night time battles.
These are a few small things that I noticed. However, it's not a huge deal, but they could have really retained the weapon storing and switching aspect.
*ahem* About to start the game now. Huge ass boss battles, here I come.