Stan, I am no expert since I have never had the luck (or $$$$) to own one but = it's safe to say that the Paramount is the standard by which all other = high-end mounts are judged. You could not possibly go wrong with a Bisque = Paramount. Plus, it is "transportable," (I have seen a few in the field) whereas = the additional weight of the MI-500 could be a problem if you wanted to take = it out. You might try the ScopeMounts group on Yahoo for more information: http://groups.yahoo.com/group/ScopeMounts/ or http://groups.yahoo.com/group/SoftBisqUser/ I imagine that both mounts are great, but it seems that the Paramount is more prevalent among power users--I see more of them in private well-equipped observatories than any other brand. Heck, even some pros = use them for "small" scope rigs that do automated surveys and such. The MI-500 would no doubt do a nice job in your observatory, and it = costs 2 grand less, so there it is . . .=20 Matt