Bt-4, with SAW stock, RAP4 Recon 8in barrel with APEX tip or hammerhead sharktooth, Picatinny raised rail with Bushnell HOLOsight Gen II on top. E-grip
Recommended Upgrades:
Rip-Clip
E-grip, but get the APE board
Better barrel, either Hammerhead or Apex
Best marker I will ever use hands down. The Holo Sight is not necessary I just bought to put on this until I get my AR15 in the future. Anyways, this gun is very dependable. Everytime I go out there it works I had one little hitch one time. It would not cycle for some reason. I later found out that Parts Washer still require the marker to be broken down afterwards. (I'm the DumbA$$)
A stock was the first upgrade that feels mandatory for me. I shoot a lot and it don't feel right without the stock.
The rip-clip came next. Very fast and easy to maintain and the batteries last forever.
Next the E-grip, However instead of having a selector type button or switch they have this switch on the board which require the breakdown of the grip everytime you want to switch rates of fire. (I can't afford to shoot full auto all the time)
Barrel is the only real mandatory upgrade, I hate that stock barrel. I upgraded to the RAP4 recon barrel with an Apex tip on it. I figured the BT Apex was just the stock barrel with an Apex. However the hammer head is the better upgrade. Rifling gives you greater stability thus better range. A5/X7 threads so there are about a million barrels for it.
At the end of my spending spree I had a marker on the heavier side about 5 lbs. Which is still much lighter than any rifle. So Adapt and overcome
In the end it was the Maintenance that was the best. I didn't have that stupid Hopper tension spring like the 98 (If you own one and have ever taken it apart you know what I'm talking about) You need one allen wrench to take it apart. Bolt assembly is the same as a 98 or Pro/carbine. very nice.
Finally Upgrades are the nicest. With Picatinny rails coming with it there are zillions of them. I see a flashlight in my future for it.
Conclusion:
I bought this as a gun to loan to friends and now its my primary. Get this All Tippmann fans will be Ben Tippmann fans. Especially now that tippmann has gone to the Plastic marker dark side.