Pros:

Resident Evil
Much Better than coach when using 3 of the other RE characters with it.
Nice port

Cons:

It doesn't go with the rest of the skins you uploaded, wrong game.
It's not just that I'm not a big fan of the one you chose but he doesn't fit well with the Left 4 Dead environment to me. In that outfit I mean, then again Nick wears a suit.
He feels too Shiny?

Conclusion:

I can't base this review solely on the fact that it's not the proper Wesker, i won't lie it really made me sad when I was running through Suicide Blitz with Jill, Chris and Barry and the wrong Wesker just kinda stood out.  But don't worry I won't mark you down for it, the port was proper and no clipping on this one like Jill, that I noticed. Then again, I was playing Jill. Improvements? I'm not really sure, besides eventually when possible being able to fix the facial animations and such. But I just don't much care for him because he doesn't fit well with Left 4 Dead. Now, that's probably why I'm so stuck on the Older Wesker would have been better bit. The other three I were using looked insanely awesome in Left 4 Dead, i was like woah, this rocks! But he just never seemed right. He also feels a tiny bit..Shiny? Almost like you need to take him in Photoshop and tone down his bright leather. Keep up the good work on your mods, I'd love you to pieces if you'd upload a version of the old Wesker so I'd have a matching set.

Pros:

It's Jill!
Much better than Rochelle
Resident Evil is awesome!

Cons:

The animations model when used as Rochelle just kind of looks silly.
When holding pretty much any gun besides pistols there is clipping right under her right arm, you can see through her. 

Conclusion:

Very very awesome port! I'm a little sad that it had to use Rochelle's animations because they make her look very odd. The exact reason I immediately just after popping in game to test the Alyx Vance mod stopped using it. Rochelle just has horrid animations, that's not your fault though. However, on Jill the animations were much more tolerable.  This clipping issue under right arm makes me a sad panda. Unfortunate because I was super excited to have this skin but once I noticed the clipping I couldn't keep my eyes off of it to use it. All in all I really do hope you update this mod, great work!