Yes many of the bus conversions are build very well. They just don't fit my need ... and I think thats the important point. You need to figure out your needs and then find the best vehicle to fulfill them.
One builder is missing in this forum, ARI
http://www.legacysleepers.com/motorhomes.php
they build top quality custom sleepers and they started now also building motorhomes. When the motorhome are build in the same quality the sleepers are, then ARI would be my first pick.