I just tried this mod for the first time today. I was a pretty avid Goldeneye player back on the N64, and play TF2 and other FPSes pretty frequently.
I tried a couple of rounds on a couple of different servers - 3 or 4 on Cradle (Standard DM), a few on Facility, and one or two on the jail level (Stacks?). I also read a bit on the forums about why certain features were implemented.
I want to start by saying that a lot of the "features" in this game feel more like engine limitations from the N64. Let me explain:
Issue A: No Damage Fall-Off. This was a huge problem for me on Cradle, where for one of the rounds the "Precision" weapons set was selected, which includes both the Golden Gun and the Gold PP7. My issue here was that since there's no damage fall-off or clunky N64 controller in my way, I could just sit on top of one of the support towers and shoot at people off in the distance, scoring instant kills. On the N64 this wasn't really an issue because you had the big clunky analog stick, combined with the fact that you had to stop moving to aim. On the Source Engine, it lead to a lot of people rushing the Golden Gun and camping with nothing to stop them.
Issue B: No random spawns. While I understand this is a beloved part of the original Goldeneye, I feel like it was more of an engine limitation the first time around - you didn't have more than four people, so why bother wasting precious system memory on random spawn locations? This makes License to Kill mode feel incredibly un-fun, due to the sheer amount of times I died immediately after spawning.
Issue C: Damage. I understand about the invincibility periods, but again, I feel that was more of an engine limitation than a feature. On the N64, again, you had the big clunky analog stick, and turning around was not an easy task. On the Source Engine, you have a mouse and keyboard. The invincibility period feels very unfair, and makes the automatic weapons (RC-P90, Phantom, D5k, etc) feel kind of useless. There were several points during a round of Aztec where I would be firing multiple bursts into an enemy's chest with the P90, only for them to kill me in one or two (non-headshot) hits from a shotgun. I can understand the need for slightly odd hitboxes, but the invincibility period feels really cheap.
Other than that, the game was fun enough, but I really think some of these "features" should be looked into and reclassified as engine limitations that just don't have a place in a modern shooter.