They will be OK - not awesome but OK
I kind of like the look of the CM.091 but doubt if I would buy one
http://www.taiwangun.com/en/electric/cm-091-p-j?from=listing&campaign-id=19
http://www.taiwangun.com/en/carbines-rifles?pr=8
Once you start getting near 200 Euros then I think I might look towards a Specna Arms & quick change spring
Then again as you keep going up in price to get a better base gun
you can reach a point where it has run away & you looking at Krytac
The P&J stuff now seems to be mainly rebranded Cyma stuff now
Yes it is better but very very very likely to be the same gearbox used in cheapo CM.515
OK gearbox, kinda qwirky v3 spring guide, 8mm cross bushings, qwirky "Lonex" type tappet plate etc...
Alright, if looking to tune up they are OK but need a bit of minor modding
(other gearboxes are a bit more simpler to tune)
Probably - well yeah I'd say better than a D-Boys, but no fancy mosfet or stuff
But then no iffy G&G ETU to go wrong either
Likely to have a few slightly slightly better bits perhaps bearing spring guide maybe a slightly better motor
BUT I wouldn't really call it much of an upgraded gun tbh, slightly improved perhaps
But would refrain from using the upgraded label if I am honest.
Yes metal receiver with some nice features/touches - could be a little cheaper to tempt me perhaps
But nothing really awesome - though little is under £200 I guess
Should stand up OK, but despite all the above rubbish I haven't owned one myself
My opinion comes from what is inside - OK but nothing awesome but pretty sturdy mind
Hope some of this helps, but if you are not going to skirmish it @ 420fps then downgrade it free at TWG ?