I'd add that I'll not use them in gas rifles either for very much the same reason.
On the WE, the nozzle is subject to taking the brunt of misfeeds...and will collapse. Not nearly as expensive as PTW parts...but a PITA none the less.
On a WA system gun, misfeeds occur...and will break the plastic nozzle/bolt, and perhaps the plastic hopup if it hasn't been swapped out. At $60-90 a plastic bolt...that ain't cheap either.
With high impact guns like these...somethings got to give. It come down to what do you want to sacrifice if something's going to break. In this order I'd rather it be:
2. Nozzle (although ouch on a PTW)
When these guns slam forward so hard to chop a bb clean in half when simply loading one into the chamber...I'd rather the $0.005 part break.