I've never understood why people buy a TM (supposedly the best guns out there, and expensive to start with) and then spend a fortune 'upgrading' them. Now don't get me wrong I'm all for upgrading guns and love tinkering with mine, but TM's are supposed to be perfect out of the box. Bloke at our local site spent a fortune on a purchase and full upgrade of a TM NGRS and I dont think it ever actually completed a single game without failing in some way. it was always going back to the tech.
Each to their own though , but tinkering with TM rifles seems to cause all sorts of issues.
Because they are good, but not perfect. More can be squeezed out of them if you really want to. Do the people who buy them and spend £1000 on upgrades get £1000 of extra benefit - well that's a judgement call only the person can make, is the extra 5 metres, or the 5% improvement on the spread of bbs at 50 metres or the slightly higher fps that makes it a touch easier for the person being hit to feel it worth it? for some people it will be, for some people they'd rather move an extra 5-10 metres.
NGRS are lovely to work on compared with a standard version 2 gear box (putting them back together is much easier!), the tolerances of TM stuff is very consistent and reliable compared with some other airsoft brands. Some love the recoil, I love the bolt stop, pretty cool features that were exclusive to the NGRS system.
They do have their faults though, mainly lower FPS but that's because they are made for the japanese market, not the west with our higher FPS requirements. Because of this the gears are perfect for the lower fps, but understandably fail when you just wack in a bigger spring.
I know that when you've spent £100 doing an event, it's your 5th event of the year, each event has an average 6 hour round trip drive, you've just done 2 hours patrolling to do a tasking and get in a contact which you lose and then feel like if you'd had a bit better performance out of your RIF that might have helped change the course of the contact, then I can see the appeal of upgrading and spending big on it.