I actually liked the new weapon sounds, for the most part. Every weapon sounded great with the new sounds, especially the RPG. The only weapon sounds I didn't like were the ones for the pistol. Felt a little out of place.
Only sounds that annoyed me slightly were when Freeman would lift his hand from the MP5 and grab it repeatedly around 3:30 into the episode. The tapping noises were repetitive and kind of annoying.
Other than that, General Cornwaffle is doing a really good job with the sound editing, it worked really well with this episode. One small effect he edited in that I really liked was at about 30 seconds into the episode, when Freeman gets hit by the xen tree. I'd imagine that'd be pretty accurate to how it'd sound and feel when getting hit in the head by something like that.