Well, we have to differentiate here between difficult to grow and difficult to bloom.....very different situations. Way back in 1986 or so, Ned Nash had a great series of articles in the AOS Bulletin about growing paphs, including "difficult" paphs, and I still find his ideas correct. For example, bellatulum is a very difficult paph to keep alive for long...but while its alive, it is very easy to at least get into spike...I find that the alba form spikes as easily as the normal form but the normal form is less prone to blasting. malipoense is certainly difficult to bloom...but I have had plants live for many years with me...without ever even thinking of setting a bud.
Multiflorals, as Nash said, are easy to grow....but difficult to bloom...especially roth and its crosses (I have only gotten St. Swithin to bloom, of all my "roths"..)
I have a philipinense that has never bloomed in the 15+ years I have had it...although it is multigrowth...(actually, it spiked as a single division when I first got it, and a squirrel knocked it over and broke off the spike...). Then again, difficult paphs can have the difficulty bred out of them...like delanatii. On the other hand, paphs like armeniacum and micranthum were very easy to grow, at least armeniacum was...in the original imported plants...they were stoloniferous, growing like crazy, and even if they kicked the bucket they produced enough offspring to carry on. Now, there are newer seed-grown clones that are "easy" to bloom...well, maybe they are easier to bloom (no luck yet for me... but they have lost the stoloniferous trait...so when a piece dies, it is dead...and you don't have spare pieces.....its a trade-off...easy to bloom? Easy to grow? Most of the time you can't have both...........Take care, Eric