I haven't used many similar products except for lesser pirahnas.
I've shot many types of cockers, spyders, tippmans, impulses and more I can't think of at the moment.
New barrel - for the price, the barrel on this gun is surprisingly good, but it benefits hugely from the addition of a barrel. I recommend the smart parts line.
Good hopper - the e-force's speed is well suited for the 12v x board
expansion chamber, if using co2
drop forward - a heavy tank on the back can get this gun pretty off balance.
very nice trigger
can't keep up with high end electros
not very accurate
Two of my good friends have these. I have played games with both, and have been extremely impressed every time. I have to work my hinge-trigger cocker to shoot faster than these guns. They are very well manufactured, the body is well milled and the anodizing seems high quality. One of my friends drops his marker all the time, but it hasn't suffered from any noticeable scratches.
For around $150, this is an incredibly fast marker. All but the most demanding (or spoiled) players will be impressed and satisfied with the piranha's speed. It can't keep pace with the fastest, most expensive electronic markers, but in the real world, it's fast enough.
my favorite feature of the e force is the trigger. it's very light and can be adjusted down. it's a nice aluminum piece as well and doesn't have to much excess play, which is rare and pleasing in the world of electronic guns.
with the right setup, this gun can be very accurate. the range is left wanting when compared to my cocker, but again, it shoots as far as most people would ever need. the good groupings (with a better barrel, I recommend progressive for the money) and great speed won't leave you frustrated at an inability to hit something. If you miss the first time, you can get another 7 or 8 shots off before they know what's going on.
I played last weekend for an entire day with my friend's piranha (my cocker is broken about 70% of the time) I was very impressed with its performance, though his spring was worn out and without a replacement, I couldn't get the velocity higher than 200-215. As long as you watch for the spring, I haven't seen any other problems with this gun, though is sometimes double feeds with smaller paints. Even with the extremely low velocity, I was able to hold my own. with another 80 fps a lot of disappointing bounces would have been sure breaks, and I still got just about everyone I should have.
For the money, I don't think the piranha can be beat. I recommend it to anyone looking to get into paintball. Stock, it's a great performer and is very simple to understand. With a minimal of modifications, it will keep up with all but the best guns. Because there are better guns, I am giving it an 8, but I completely recommend it. It's a 10 in the under $300 range. Just remember to keep a spring handy.