A lot of what is in SAS d20 can be found in BESM 3.0 and SAS. A lot. So much that I wish I had just one omnibus edition with say a d20 conversion chapter. Almost all the attributes have the same (or similar) point spread across all the systems and to convert to d20 from Tri-Stat is often just a matter of doubling the points. BESM d20 includes rules for converting the D&D and d20 Mod classes to their point system so I am not at a lack of choices. I did notice right away that BESM d20's Dynamic Sorcerer is not 100% compatible with SAS d20's Costumed Wizard; and similar inconsistencies have popped up. There are also minor balance issues between the SAS classes and between the SAS and BESM classes.
Levels, Classes and Hit Points
Ok, lets get this out of the way now. SAS d20 both have levels, classes and hitpoints. I typically find that people can deal with one, but not the other, and rarely both unless it's D&D. On the surface level can convert roughly to M&M's PL, rough enough that I am going to say it's fine and not worry about it. But Hit Points do not work with M&M's Damage system.
And then there are Classes.
While some don't like this, I think it works well in terms of Anime, but less so for Supers. Ok for the most part these can be ignored since they only decide what powers a character will get and when, what Hit Die, attacks and saves. We can convert the Classes to archetypes but we are still stuck with levels. It is d20 after all.
The SAS d20 classes felt too restrictive. The classes in BESM d20 seem to work better for me. One thing I wanted to do was stat up my son's favorite female super heroes Fire and Ice, but the closest thing that seems to work is "Adventurer" with maybe some "Acrobat"? Not very satisfying. At this point I go to my d20 Modern and Mutants & Masterminds to get an idea what levels might be the best.
Once that is out of the way the rest actually falls into place really nice.
What gets me about SAS d20 is the huge amount of untapped potential here. There is just a ton of stuff in this book for the taking.
Plus SAS has the best super-hero history I ever read was in the pages of a Supers RPG. They are the same in both the d20 and Tri-Stat versions (another grumble). SAS looks like it should mix well with M&M but I guess they are really too close to each other that their differences are more obvious. It's a shame that SAS never really got it's due. It does read like a rough draft of M&M at times.
Is SAS d20 a great Supers game? Hard to say. It has a lot going for it and in some ways is a better d20 game than Mutants and Masterminds is.
I have to reiterate what a shame it is that we lost GoO. I know companies come and go all the time and each time something unique to the industry is lost. Not to say there were not issues with GoO; there were plenty, and they were hardly a model of how to run a business. It is just too bad that what they provided to the game industry is now gone.
This game is so close to a 5 out of 5 for me. The flaws are only more vivid because so much of this game is so good.