My personal opinion about such things, irrespective of the course or the instructor, which I assume by SDI will both be adequate, is that solo diving isn't something you can ordinarily learn in the "compressed" format of most diving instruction.
Why I think this is as follows: Most diving courses... and I believe *all* diving courses from mainstream agencies like SDI are structured--for better or worse--like this:
1) you learn some theory, which is performanced based -- all good
2) you learn some skills, which is performacnce based -- all good
3) you get limited experience applying those new skills and knowledge in real-world diving circumstances -- in this case.... *not* so good.
The problem I see is that you don't really get much experience given to you under supervision during the course... In fact, you're expected, after most diving courses, to go out and build up a base of experience *after* the course is over. The debate about whether or not this is good/bad is irrelevant. This is how it works.
In this particular context, I believe that this is "putting the cart in front of the horse" because I believe solo diving is something you may want to embark upon *after* you have a base of experience to work from and not that you can expect to be made "ready" by taking a course.
The main alarm bell that I get is that someone who feels the *need* to take a course about solo diving may not, in fact, be ready to start with it yet. Having said that, if you *do* feel that you are a good enough diver and have the base of raw diving experience, then such a course will certainly give you the peace of mind of "double checking" that you had, in fact, thought of everything.
R..