I was very much in the same boat as you when i started Airsofting
Didnt want a Glock, wanted the M9 but in metal, since TM was all plastic it must be s**t right? Compared to a full metal gun, oh how wrong i was!
My first pistol was a WE M92FS Samurai Edge (Resident Evil) M9, loved it to bits but only for the looks, performance wise without having anything to compare it to i always still thought this should be better?
It could barely lift .25g BBs i could see the shot dropping after about 30 feet
The blow back felt pants unless you used the CO2 Mags
Using CO2 mags the accuracy was WAAAY off, shot going in every direction
Mags leaked frequently even with care.
Hop adjusting was a nightmare (small screw on top of inner barrel require almost full disassembly)
Very gas inefficient
On cooler (not cold) days the mags would vent after 6 quick shots
Irregular FPS at time
Slide wouldn't lock back after last shot was fired
Does not use TM standard parts
It didn't fit my real steel Blackhawk Serpa Holster
Eventually it broke, think a sear came loose or something but i was so pissed with it i couldn't have cared less and gave it to a friend for free, thats how bad it was. As for the fitting in to a real steel Blackhawk Holster, its not the fault of WE, the Resident Evil M9 has the Brigadier Slide (as it does in the game) and this slide is fatter than the standard M9. Blackhawk themselves state that M9s with the Brigadier slide wont fit their Serpa holsters.
Went out and bought a TM M92FS and a couple of mags and straight away notice a few things
The hop up could lift .25g BBs
The Hop up was amazeballs, i was ranging AEGs accurately
Hop Up adjustment was easier
Blowback action was harder hitting and crisper
Even on cold days the mags wont vent
Gas Efficient
Very stable FPS
Slide locks back properly
Engaging safety decocks the hammer like on a Real steel M9
Fitted my real steel Blackhawk Serpa holster perfectly
Thats not to say its all rosy though:
Sometimes the mags do leak, last time this happened to me it was because i left them overnight fully degassed only 2 of my 4 mags had leaking issues which were fixed.
The safety does not always decock the hammer, but only if you engage safety on the left side of the gun, it i do it on the right side it always will
Yes it feels a lot lighter than a metal version of the M9.
Now i know the above sounds a bit fan boyish for TM but trust me the above came through experience having owned an M9 from both WE and TM i can with full 100% conviction state that TM is by far and a way better, forget the fact its made of plastic, it does not bother me and it wont bother you. I would recommend you get the TM M9 and leave it stock, dont bother getting aftermarket parts for it or you might break what didn't need to be fixed.
If you MUST have a metal M9 then i suggest you look at the KSC M9, it is about £50 more expensive than the TM and needs to be treated more kindly as KSC stuff is normally a bit more collectable than skirmishable.