having used all of the above and having owned and ion and got rid of it, and the trilogy, i would recommend the cocker everytime. just as reliable as the 98 without the fugly looks (ok the looks are a personal thing), its shorter, comes with a better quality barrel of a decent length, unlike the 98, and is inherintly accurate.
as for the ion (ion owners might not like this), ive owned two of them (technically only paid for one), and they both kept breaking down, had one replaced by smart parts because of this but that one didnt last long either, so i sold it onto someone who wanted it for parts. im not trying annoy people just saying what happened to me so please no flaming.
so, in short, cocker trilogy is your best bet for woodsball. mine was the first paintball marker that i bought and its the only one out of every gun ive owned that i KNOW will work with no problems.