Tippman A5 and 98 and one or two Spyders and the SP8.
Kingman Spyder MR3 with just a VLocity Viewloder and a Pure Energy 1.1 Ltr 4500 PSI Fiber Rap Tank so far - Hey I need to use it a few times, and see what its strengths and weaknesses are before "pimping" it. Its about buying the right parts not showing how much disposible income you have!
So far none but I'll try and update you as I use and abuse the gun!
Grip Panels fit too losely
Without a stock attached the bolt is 'open'.
I bought this marker after selling an A5 and rather than an SP8 and I'm not sorry I bought it! Well this marker is solidly built. Its easy to take apart and clean and its easy to put back together. Much, much easier than my A5! It is metal but for the foregrip (which is VERY solid plastic and the grip covers that house the electronics - more on them later) and feels like its not about to break through vigorous woodsball. I also found the gun quite 'ergonomic' - something which is much more important than looks! I've used it only twice so far but each time it was for almost a whole days play (6 to 8 hours) and I fired off 1500+ paintballs. Even with the stock barrel it is on target and reliable over a reasonable distance in normal conditions. The whole time I used it I had just one ball burst in my barrel and I think that was only because while crawling through a bush I managed to get a twig in it.
Now this where my lovely new marker loses its 'perfect 10'! The main with the MR3 is small, but could potentially store up problems for users because of a requirement for maintenance, and it is also something I feel Kingman could and should rectify. The "270 MR3 Grip Panels" on the MR3 are not a perfect fit and as a result there is a narrow gap that could allow dirt and moisture to get in and damage the 'brain' of your lovely MR3 (If there was an option, I'd post a pic to show you what I mean). The other minor problem is without the stock attached, the Venturi Bolt is 'open' allowing dirt to get in to your marker. If you want to attach a tank direct to your marker you'll want to remove the stock. Kingman or some after market supplyer needs to produce a 'cover' to protect your marker from dirt and grime when you don't want to use the stock (again if I could I'd post a pic, but you can go on the the Kingman site and open the Pdf. manual and have a look for yourself).
All in all the MR3 is one of the best woodsball type markers I've used. A good reliable marker which misses out on a 10 because of two minor problems that hopefully Kingman or an aftermarked supplier can hopefully sort.
Just to comment on you faults I agree with the grip having a small gap to allow dirt and moisture in. In fact I had to worry about that this weekend, and little tape helped but no real problem slover. So yes this is a issuse.
Also the open bolt problem I sloved its easy as taking the stock apart more then you need to. If you look there is another allen head screw in the stock futher back then the one you have to put in to attach. the stock. So in taking that apart you end up with a plug for the back of the bolt. Only problem is a little cyclender of metal over hang. To me it did not get in the way of movement or shooting.