I think that depends entirely on what are you planning on training him for and who your main market will be. The dressage world in these parts are well, not the highest quality in the country, and judging by the shows I've been to don't seem to care too much. None of the hunter trainers around here really care and the jumpers definately could care less! They'll buy anything as long as it can do the job. I do have to say that I would tend to veer away from breeds that aren't typically seen successful in the field. Like if someone claimed their saddlebred cross was a beautiful 3"6 hunter? It would have to look and move a whole lot unlike a saddlebred for me to be interested in it.
(before all the saddlebred lovers out there attack me for saying that and tell me about so and so's saddlebred who was horse of the year and a beautiful jumper and all of that.... I'm using them as an example! they're not made to be hunters so the vast majority of them will not be successful in the upper level shows! don't hate me.... i love your horse...)