I also run a MX255 and I agree with the other posters that you will prob. be better off with the 245.  It is true you could put a mechanical fuel system on the 255, but very likely that will hurt resale value.  Don't know that for sure, but I do know that not everybody has been able to make the mechanical pump work like they thought it would.  I have 4,300 hrs. on my MX255 and on the second CAPS.  The first one the dealer helped.  I'm not necessarily scared of the CAPS, but you need to be careful and never run it out of fuel and keep the filters changed regularly.  My dealer techs have told me that once the first CAPS system was changed that the second one did not give trouble.  Don't know if they improved the design or what happened?  There are shops rebuilding the CAPS now, which wasn't available earlier.