still won't have the simulated recoil or functioning bolt catch and if you think simply a shimjob, m100/m90 spring, and bucking + nub is going = better than TM quality ur a silly man. TM full metal bodies are 10x better than CYMA pot metal bodies and the internals are still much more reliable than anything you'll get in a CYMA. CYMAs are decent guns for their price but don't kid your self by saying that a few minor upgrades is going to set it at the same level as a TM. TMs are great guns, if you leave a TM stock it is going to have superb exterior quality, supreme performance, and unquestionable reliability, the only caveat is a lower FPS which doesn't matter because the hop-up is going to give you excellent range.
The price is high compared to other options but denying TM as one of the best brands is dumb, I'd rather skirmish a TM over a CYMA/JG/whateverotherchinaclone any day of the week.