Myself I can only speak for TM SCAR-L NGRS, as I left regular TM AEGs behind years ago and went with different brands.
NGRS is fun and I especially appreciate the more realistic manual of arms without the hassle of dealing with gas mags. That's about it.
Modern TM charges stupid money for well... "subpar" quality exterior finish (in case of SCAR-L it's just laughably bad and wobbly ABS plastic, feels like made out of B&Q plastic pipes) and not so great out of the box performance. I've seen and handled VFC SCAR alongside TM SCARL and difference in built quality is just mind blowing.
The fact that you have to spend more money to upgrade it with special NGRS TITAN, a bunch of (not cheap) internal parts just to get it to a skirmish standard is pathetic for the cost. Total cost brings you closer to already beefed up GBBR.
I was lucky enough to get mine second hand from a friend with all the upgrades already done for a reasonable price, but to be fair I'm still trying to decide if I didn't waste my money.
That is just my experience with my replica, though majority of Youtube reviewers laud TM NGRS as the best there is om the market, but fail to mention many of its shortcomings.
Modern market is full of well made and affordable airsoft replicas. Marui as a brand still has place in the market with their innovations for the hobby, like the ZET system for GBBRs, bolt release and cut off systems in the NGRS or the newer versions of the gas pistols. Its the mind boggling price system and crap materials they use for the externals of their replicas that prevents them from still being the top dogs.