I have not. I’ve never even seen one in person. I am quite comfortable in Boxster's and Miata’s. I find C4 and C5 Corvette’s coffin-like but I think that’s due to the high belt line, I fit fine. I fit but was not comfortable in a Honda S2000. Now I have a new mission. Find and sit in a Spyder. I understand Speedsters are roomier.
Yeah - everybody can get comfortable in a Boxter. Almost everybody can get comfortable in a Miata. This is not that kind of car. An S2000 is roomier than a Speedster, which is a lot roomier than a Spyder. The cabin is tiny.
If you're long in the torso you'll likely find yourself rapidly running out of fore and aft adjustability and may find it nearly impossible to get behind the windshield. You'll never know without at least sitting in one. I can't stress this enough - please don't make a $50K mistake.
I'm sure there will be somebody who's 6'7" and 175 lbs who will say they fit just fine - but if you're 6 ft tall with a 32" inseam, or if you weigh over 220 or so, you may not fit. Before heading any further down the rabbit hole, find somebody to ride with.
I want one of these cars in the worst possible way. I've got it really bad. But I just don't fit - period. Beck, Vintage - doesn't matter. I need my butt a LOT lower and the seat to slide back another 3 or 4 inches. All the usual tricks (tilting the seat back being the easiest) are not possible, as it only exacerbates the problem of no fore/aft room.
Nobody wants to hear it, but it's the truth. You've got to try before you buy. There's a show in Carrlisle, PA in May and a get-together in the Smoky Mountains in Sept. I'd recommend going to one or the other.