Need a new gun.

I know where you are coming from; I had same entry process and went from a Crossman nitro piston to a Day State. You have great shooting skills,but a gas piston (Benjamin Trail NP2) still shoots like a springer - needs skill, artillery hold, etc. A PCP is a different animal altogether; much more accurate for the same skill level. Unfortunately, its also more expensive when you factor in all the extras. At a minimum you need a pump, but after you get tired of that, a carbon fiber tank will make life much nicer. Also, once you get a PCP, you will appreciate a scope much more (unless you are super skilled) than open sights.

Definitely steer clear of the nitro pistons, they're harsher than the springs and much much harder to work on.
If you're looking at a Disco, scoped will come to about $500 but you will have a light gun that requires little skill. Al thou it is super loud, you will want to get a LDC in the near future.
For less than that you could also get an RWS 350 Magnum, which with a good mount designed for it and a Leapers (good bang for your buck) scope should not disappoint and will shoot as accurate and about as hard as the Disco, althou heavier and harder to master.

I'd keep an eye on the specials and used gun section on Airguns of Arizona, here's a link if it helps.http://www.airgunsofarizona.com/
You probably could have found it on your own, but oh well better safe than sorry. ;-)

I was in your same situation about a year ago but went ahead and got the Discovery uprading from my Benjamin Trail Np. And the difference was amazing. The Discovery was more accurate, easier to shoot, and wasn't as heavy. Since you only have to pump this up to 2000 psi and not something like 3000 it's not bad at all really, just time consuming. For target shooting I got tired of pumping but for me 20 shots for hunting worked out fine. And as for taking down coons no problem at all i've killed about 7 of them and i've also knocked a ground-hog out at fifty yards before in the head. They just flop on the ground and there done. I recommend getting a used Discovery like i did just make sure that theres nothing wrong with it. I got a leapers scope, the gun, TKO muzzle brake, pump, some pellets, and there was some upgrade on the trigger for only 350$ that was one of the best deals i saw and the guy only lived 20 min away so if you want to save money i would try doing that.
Leo : )

If you want your scope to stop sliding you are going to need a one piece mount. This will clamp onto the rail more firmly and stop the scope from coming back.
Also make sure to keep your eyes open for used guns you might find a great deal.
Leo