Actually, one can do alot of DIY works to make theirs perform better.
There's alot of DIY hacks online that you can replicate.
TM's good, but quite abit needs to be spent if you're going for the metal slide and all.
WE's Achilles heel is it's own weight. It's internals are made of pot metals which is quite soft with accelerated wear and tear IMHO.
A good & cheap candidate is the KJW's KP-05 or KP-06. It's full metal & the internal's are with real metal, so it's good for high milers. It also comes with adjustable triggers and two mags (1xpropane gas, 1xCO2)The downside is the slide's pretty heavy hence the slow return to battery. A set of 150% recoil spring set will make it much better.
There's a cheap C-More Serendipity replica selling for around USD50.00.