Heh look an opinion over here!
So, I've used a few of these side-arms and it is quite a lot of fun. If you end up buying a side-arm, you'll get to play an entirely different game simply by the gun your using. Playing with a side-arm brings a whole new novelty to the game you've played many times before. Limiting yourself to ten rounds and having no option but to aim and move in on an enemy really makes the game more challenging and lots of fun.
Now, I'll admit that this sort of gameplay is not for everyone but it is an entertaining change of pace. Even if you have a main gun, it is fun to bring a pistol for when you tank runs out of gas and your not close to a refill point. 12gram CO2 cartridges don't weigh a lot and can extend your performance all the way to a resupply point on scenario fields like D-Day. ...And as someone mentioned in an earlier reply they do look cool.
If your looking to get a pistol there are a couple things to think about. Some of the side-arms come with tactical rails, holsters, built-in quick changes for your 12 gram CO2 cartridges, and other cool features. These features can be useful and they can also just get in the way.
1:Tactical rails give you mounting options for tac. lights, lasers, and other cool devices. The downside is if you attempt to put a pistol that has all these "extras" on it in a holster, it more than likely won't fit. Now your gun is also heavy. Use your side-arm enough and the weight will become quite a factor in your enjoyment of your pistol.
2:Quick change CO2 cartridge adapters... A good idea, but also a plague to most that use paintball pistols. A Quick-flip quick change allows a player to pop out a 12 gram cartridge and load another cartridge rapidy, cutting down on the reload time of your marker. A quick-flip will also expel all the remaining CO2 onto the o-ring that seals the point that a cartidge gets pierced. After quick-flipping a few times this o-ring will be destroyed. Replacing this o-ring requires one to dissasemble their side-arm and then re-assemble... Not something you want to do on the battle field.
3:You may also want to find a vest or holsters to fit your new side-arm. This is the easy part. You can find many holsters pre-maid on many paintball sites to fit any paintball pistol made to date.
4: Price can also be a barrier to many looking to get a paintball pistol. Paintball pistols can cost $300-$400 dollars for the really nice ones like the air gun designs syd-arm. $100-$150 can get you the pistols with the tac rails and other quick flips and etc.
5:With all this in mind I personally enjoy the simple things in life. The PT JR is my choice of paintball side-arm. If you've read this far, I'm sure you would probably like to know why... The PT JR is small, actually the lightest side-arm made. The JR has a quick threaded screw-in CO2 changer. This basically means that you can still change your CO2 in a relatively good amount of time, but you will bleed the remaining CO2 instead of dumping it. This difference is definately worth the time. The PT JR is by far the right choice for someone who is worried about their wallet, coming in at only $79.95 @ www.gatsplat.com
At that price you could get two and go Akimbo!
Anyhow, I obviously write too much, but I hope that helps you pick out the right side-arm.