The Axe is a great gun. It will be smooth enough and more than efficient enough for the average player. It is simply to work on has great customer service and can generally be fixed by any field in the USA.The board takes some getting use to.
the reflex rail would be my second option it give you a gun that is as close as you can get to the DM series without buying one. They are relatively simply work on and diagnose, also will fire very smooth in comparison to a poppit style gun.
Etek 3 is a very durable gun will require very little maintenance, But it will be louder than the others and not as smooth in operation. I also personally don't like the board when it comes to adjusting settings.
as for your last option the DP FX people will have conflicting opinions but i have had relatively bad experiences at my field with them and the other guns in that price range are much better choices.
In the end i highly suggest that you attempt to shoot all the guns at a local field before you jump ahead and purchase one. They will all feel different in your hands and ergonomics will mean alot when you have to hold the gun all day long.
I have shot and maintained every gun listed here (i am a working gun tech at a field in Connecticut) and i think you willl be very happy with any of the top 3 i listed (axe/reflex rail/etek 3)
Matts Outback Paintball
Former Fuzzy Bunnies Captain
You gas up the marker, put on the gloves, strap on the mask, and walk onto the field.. it doesn't matter that you failed a test, that your girlfriend broke up with you last night, or that you got a ticket on the way there... your world is right for the next couple hours, this is your heaven on earth