Patsu there are many sections where a bunch of enemies are on screen and that is impressive for the most part, but on the 8 player coop it just bored me to death. Every enemy in the coop takes ridiculous amounts of ammo to kill even when all you do is shoot them in the head and they rarely rush or flank the players.
I don't think every enemy takes ridiculous amount of ammo to kill. The drones, Grims, regular hybrids and Ravagers are not difficult to lay down on a one-on-one, and one-against-many situations. The Steelhead, Alpha Grims, Titans, Stalkers can be annoying when you're playing as a low level soldier (Takes too long to kill). You'll need to team up to retire them.
As your level advances, they will die faster. At the same time, the AI will improve noticeably. You'll see them rush, flank and team up against the human players across greater distance. In fact, they will hunt you down one by one if you're too dispersed. The Steelheads can also see you even if you hide without firing. This is where things become MUCH more interesting for me. At the same time, it will become harder to complete co-op. As they say, "Don't pray too hard, you might get it". What you saw may not be representative of the final co-op gameplay.
The map variety is also very limited.
I think the map variety is more than sufficient. I played the beta for about a month
on just 1 co-op map, and still see some rare map variation towards the end. It's the enemy spawns that should be varied.
As for where I died a lot, it was throughout the entire campaign tending to be when the game threw a bunch of enemies at me. I think the short health, slow regen, and enemies only targeting Hale just make the game very unforgiving on any difficulty. The boss battles were for the most part the easiest part of the game.
I am replaying on Difficult (and I am not a great FPS player. My R1 K/D is only about 1.1). I agree wholeheartedly with you that the freaking health bar is too short. I think Resistance forces you to think fast. I find myself retreating and making use of the terrain and choke points very often.
I am still experimenting with the "AI focusing on Hale" problem. It only happened to me 3 times in "Normal" (I usually hang behind the Sentinels).
When I said skirmish 60 player felt to small I was referring to the way the maps and the objectives keep the game broken up into just one or two squads against each other for most of the game.
I think there are not enough players yet. Most people are tied up in different games this fall.
There were several times when I had to run off in search of a weapon because it wasn't in the obvious spot prior to an encounter.
Yes, happened to me twice against Titans. Like you, I do wish the wheel make a come back (or lengthen our health bar). The ALT fire of various weapons are pretty useful in R2, but I didn't get to play with them too often. Had to switch weapons frequently.