so far (for me at least) the 904 has worked out quite well, the 904 speedmaster has circumnavigated the great lakes, twice, as well as numerous trips 500 to 1000 mile weekends and a trip from Wi to the black hills. I tend to ride hard (like it was stolen) and put in long days. I have no complaints about the reliability of the 904.
If doing over, I would be a bit more hestitant to go with the 12:1 compression, not because of reliability but because of fuel availability, several times got into remote areas where only low octane could be had and the motor did not like that. Realisticaly 10.5:1 or 11:1 would be more viable for the street.
on the other side, I have a speedmaster with over 90hp at the rear wheel and it is just plain fun to ride.
