Inside isolation gdp is the same as base offense's aka balanced/normal
er.. it's a weird offense and no one is 100% sure what the outcome of it will always be (i dont like to use it ever unless im throwing off a gdp or it's an easy game)
basically one of your bigs will become the primary ball handler, like a PG... but at PF or C... i'm not sure if SF is involved. It doesnt mean he'll score, but generally a SF or PF may score most on this offense. Or a guard, since they can become open when all the attention is being paid to the big. It's not an inside offense at all, hence the gdp isnt inside. It's just that an inside player as i said before handles the ball the most.
if you have a big with good handling/passing/driving he should be amazing on this offense and you could consider it as a regular option though.
and it's basically vice versa with outside isolation, guard handles it primary, kind of like Harden for the rockets maybe? but not guaranteed that amount of scoring. It's possible though depending on your team build.
and i'll go back to my cave in barbados now ;)