Autococker- different price range, so really no comparison applies
Piranha/Spyder - Way way worse for entry level.
2k2 v/f Cocker w/Kapp Rflx hinge, Palmer's Rock, Bomb, Fat Ram, Ergo Reg, ANS Quick Pull, Dop Drop and a bunch of barrels.
3 F4 illustrators, with all sorts of upgrades (Drops, WGP Regs, Expansion Chambers, barrels)
1- Barrel (J & J or Big Shot are by far the best)
2- 9v Hopper (After a day, you will out shoot a standard hopper garaunteed)
3-HPA (Nitrogen Tank)
3-WGP Reg (get em off the boards for like $15-$20)
Consistent (nice accuracy)
Easy to Maintain
Great Customer Service / Owner's Group
For this price range, there is absolutely nothing anyone can complain about. (PERIOD)
What can I say? I started with an F2 back before HPA or Electros, and the F4 is just a solid more sleek version. This gun is THE entry level marker. Nothing else comes close to the quality and reliability of this marker for under $150 new or under $80 used. I have bought (for myself and friends) a total of 5 used F4 Illustrators, and all of them have operated perfectly even in near freezing temperatures on C02.
In terms of quality, there is no comparison to the spyder or piranha, which are continuously in need of repair and perform at a much lower level.
Furthermore, I used a tricked out F4 for a long time before I got an Autococker, and with its range and accuracy I was consistently taking out players with much more expensive markers.
I highly recommend this marker for anyone new to paintball, or if you need a reliable back up/loaner. You can go on the forums and find cheap stock cocker regs for $15 or so and grab a new barrel, and a drop and the F4 will not let you down. And do not hesitate to read more about the F4 at the F4 owner's group site (URL's are against the rules, sorry)