There should not be any appreciable difference in any remap that's done properly ie. it's the right one for the engine etc.
It is possible the re-mappers are effectively just agents and do no development work at all ie. they all buy the same remaps from a specialist developer who has the expensive kit and know how (and maybe access to the next generation OE mapping).
You dont really need a dyno (but yes it's nice to have one) - if you can't detect a major increase in power, torque, smoothness and flexibilty through the whole rev range then youv'e been ripped off (or it hasn't worked). You should be reaching for 7th gear on the first decent straight (or 6th if you only have 5).
Last edited by rt05492; 31-07-11 at 17:57.