Bought this for shits and giggles from buyairsoft.ca, hoped to turn it into a loaner/emergency backup gun since its small and doesn't take up much room in my bag.
Fairly solid, no major wobble or creak, then the handguard is secured with or without the battery in it there is no wobble. The stock when pulled out wobbles less than the TM MP5's I've handled. The stock does jam from time to time and you need to give it a really good whack to get it to collapse or a solid tug to open it, the lever that unlocks it also sticks so you need to manually turn it to lock the stock in position, TM models I have handled snap back on their own.
The battery actually worked out of the box, can't say the same for my Kraken AK, crappy charger, stupid little sling, cleaning rod that snapped coming out of the package, and a bottle of crap quality BB's are all included.
The hopup is the v-type so isn't compatible with normal rubbers. The Kraken AK hopup assembly is easy to swap with a TM compatible one so this one might be as well, haven't checked. The selector has a really nice solid click to it, big downside is that it doesn't have the HK markings but "safe" "semi" and "auto" printed on the plastic. Plan on repainting this and engraving something funny, possibly zombie related. The stock mag is the double hicap shorty type and feeds quite well but is a bitch to load, I have never handled a TM one so I don't know how hard they are to compare. The hopup adjustment lever is far stiffer than any TM or ICS I have used. One big thing is the gun is useless on semi, sometimes the BB drops 5' in front of you, 15', or goes straight for 100'. When firing on auto only the first shot seems to have flakey hopup and the rest go nice and straight, far more accurate than I expected (but still within the accuracy expectations of a 350fps MP5.) I didn't have a chance to get a precise chrony result but from my experience and seeing how fast the BB covers ground I'd say its between 320 and 360fps, BB's are definitely moving faster than a stock TM.
I paid a touch above CAD$190 to my door from buypaintball.ca and in my opinion is okay for a loaner/backup but I would not recommend these for a first/primary AEG for a new player. The only reason I bought this is because I know how to work on MP5's quite well, first time buyers should stick to TM/CA/ICS/G&P/etc. or if you are on a budget, JG or Echo1. I will be running this until it breaks and then doing a complete upgrade, until then I wont be opening it. As for buypaintball.ca as a company, I found they had very good service and contacted me about a problem with the order and had it corrected in very short order. Service-wise I am quite happy with buypaintball.ca.