In general (generalization and not necessarily true for each and every one)...KWA PTP pistols shoot really hard. That's a good thing right up until they blow themselves up. Broken barrels, broken slide, bent internal and blown nozzles were pretty common on their 226/USP/M9...but did they ever shoot nice right up until they broke
On serveral occasions they shoot above and beyond some typical indoor field limits (i.e. 350fps w/ 0.20g bbs). I've see quite a few shoot 380 easily and even top 400fps (which is amazing for a GBB pistol).
On the upside the new System7 is supposed to be very efficient in gas consumption.
I like the KWA's and they're nicely made for sure...but I hate replacing blown parts in pistols. Gas pistols, in general, are fiddly to work on. Sometimes no issues...other times you just want to junk the pistol.