Let me just preface this by saying that I am a VERY new pump player. The only pump I previously owned was a PGP 2k. So there will be no comparison to a vast majority of pumps on the market, simply my first impressions from today.
I'm primarily a 3/5-man tournament player. However, being in the mid-west, my local field isn't putting up our airball field until it can't freeze since they use water bladders. As much fun as it is to go out against rec-ballers with my Ego, I'd rather not be "that guy that has an expensive gun" and gets swapped back and forth from team to team depending on who is losing. So, I wanted something cheap to throw in my trunk and use whenever I'm not practicing. Lo and behold, I find a used KP for $75. Reading decent reviews, I picked it up without really expecting much.
I got it in Friday and had to work 13 hours on Friday and Saturday so I didn't have any time to tinker with it. I did however see that one of my Vice bolts fit the marker perfectly and it actually fired. Chrono'ing with the new bolt and .678 Eigenbarrel put my velocity at 370+ with the velocity adjuster all the way out. The previous owner had mentioned that the trigger spring was broken. It was in fact the sear spring. But the sear still engaged the striker 3 out of 4 times. Obviously, the faster I pumped, the more of a chance it would not catch. The pump seemed light (compared to my memory of the PGP). I enjoy having a return spring as well. Overall, I really like the ergonomics of the marker. It feels very good using my Crossfire stubby tank. Even with my Rotor sitting on top.
Hit the field early today and it was supposed to be rainy all day. I wanted to at least try the pump so I took the S3 reg off of my SL94 and popped it on the KP. It immediately shot at ~285 (my field limit). I was pretty stoked to go out and play a couple games. My first match I was able to pick off someones hopper and felt good getting the first "K" with the marker. After 3 games, I noticed I had only used the paint in my hopper. I was ridiculously impressed with the lack of paint usage.
During the lunch break I stopped by the chrono to make sure I was still shooting okay. The marker seemed to be shooting low but I had been battling double-triple-quad feeds all day (damn sear spring - and my newbie pumping technique). Step up to the chrono 282-282-282-280... holy crap! Well that works for me!
After midway through the day, I was that "damn pump guy". I played a game where I had a ramping electro laning on me and I was able to snap him out. I just couldn't stop giggling as I ran down the tape to shoot another person. A couple other games I lobbed single shots in to gog someone and hit someone's hopper. Over the course of the day, I shot about 600 paintballs (and that's including what I used to chrono my SL94 and tune my buddy's DM7). I used about 1400psi off of that. So I would be getting somewhere in the neighborhood of 1,600-1,700 shots off a 68/45.
The bottom line for me is this: this is the most fun I've had playing paintball in a LONG time. I think at least one of my teammate's will be picking one of these up as well.
However, here are some of the cons I encountered:
Farting - It was really bad at times and other times the shots would be as silent as a DM. The shots seemed to be going to same distance. I couldn't figure that out for the life of me. I read on here about getting new springs which I very well may do. Don't know why some of my shots would be completely silent though.
Double feeding - Not the marker's fault since I suck at heavy firing with the pump action as well as not having a fully functioning sear. Regardless, it sucked when I would shoot 3 paintballs and they either lob with no power or explode in my barrel.
Here she is after a rough day. The barrel had most of the mud cleaned off while it was in my barrel wrap: