I was just using my 4" Takahashi refractor last night and even though the air was less than terrific (slowly waving in and out from really great to not great), I was picking out the most amazing amount of detail on the moon and planets.
I don't believe one particular brand or type of telescope is magically better than the others, but darn it all if Takahashi refractors don't keep delivering details and performance one just don't get with a lot of other scopes.
At one point I was up to 264x and Saturn's rings were so sharp and well defined, it was just such a thrill to see so much detail. I was also super impressed with the 1.6x Extender Q. I must admit I had my doubts about adding more glass to the system, but in practice, I can't see any image degradation at all (and I was really looking for it). I am sure there's a small amount, but not enough to worry about.
I honestly don't think it really matters which version of the FC-100 you get in terms of performance, they are all going to amazing. Pick the one with the focal length and tube assembly design that best suits your personal preferences. Every version fits into its own niche and serves a specific purpose. If you're an astrophotography addict, the FSQ might be your best choice. If all you care about are the moon/planets, then the DL might be it. If you want the best version that can do everything exceptionally well, then I think the new DZ is going to be the top of the list. If I didn't already have one, my order for the DZ would already be in, that's going to be one heck of a great scope. I just hope they will make a 5"+ version. A FC-130DZ at f/8 or even f/9 would be out of this world. Who knows what great plans Takahashi has for new scopes?