there is a forum specifically for this
I will tell you this. Internally the markers are absolutely identical. I would "invest" in neither of them. I would look at a GOG enmy or if you want tactical looks: a BT (owned by empire) or a kingman spyder MR series.
Those tippmanns are bulky and unupgradeable. They arent stellar performers out of the box and you can't get much more out of them. If youre set on tippmann get a 98c or an A5