I've owned and shot a few paintball guns over the years including a tippmann 98, tippmann A5(mocked up for scenario), Dye DM4, PT Extreme pistol.
I had a flatline barrel for the 98, and it was an inaccurate piece of shit that broke balls non-stop. It puts backspin on the ball which actually causes it to dramatically slow down at distance, and tends to curve the ball to the left or right. I had guys that could actually see and dodge long shots coming at them, LOL.
The paintball pistols are also pieces of shit.
The Dye Dm4 was the only gun I owned that performed near flawless. I haven't played in 7 years, so I'm sure they've gotten even better since then.
Tippmann 98s are great if you want a cheap beat around gun that you don't really have to care about too much. But, they can chop the hell out of balls too.
Do yourself a favor and pick up a decent used tourney gun off ebay like an older bob long, shocker, or Dye Matrix with a compressed air tank, barrel set, and motorized hopper. I still have my DM4(bought used at the time), and it came with a full parts kit, so it's still going strong. I've seen some used older DM4 setups for as cheap as $350 now. The equipment value depreciates very quickly. That's at least what I would do instead of dropping $400-$500 upgrading a tippmann "scenario" gun that doesn't perform anywhere near as well as a good used tourney gun. The tourney guns have a photogenic eye in them that sense when a ball in loaded in the chamber before it will fire, so it essencially elminates balls being chopped by the bolt.
Co2 tanks are cheap, but you can't play in cold weather with them and they vary in pressure from shot to shot so you get alot of inaccuracy and alot of ball breakage. If you get a tourny gun, you'll have to get compressed air. They have regulated air flow, aren't affected by cold temps, have less breakage and consistent shot to shot placement. It's night and day difference.
If you buy a used compressed air tank, you might have to get it hydro tested if it's been beyond the 3 or 4 years of manufacture date, which usually runs about 25 bucks, but something to consider when pricing. Co2 tanks also have to be hydro tested.
In my opinion, if you are looking for better long distance shots, get a decent multi-length, two piece barrel set (should be micro-honed mirror smooth finish inside). This cuts down on ball breakage, improves accuracy, and sometimes lets you shoot a ball break clean from the barrel. In combination with a tourney gun running compressed air, you should be able to accurately upwards lob shots at great distance on open fields. Overhanging tree cover might be a problem for distance shots, which the flatline was supposed to be good for, but with all the crazy ass shots you get out of it, you can't even hit someone at close range. At least that was my experience with it.
Hope that helps,