The advice to try before you buy is sound. The floorplans can be deceptive, not taking into account the taper at the end. I find headroom more of a problem than length, again you need to get inside to have a look, I borrowed a tent that theoretically had plenty of headroom, but only if you stayed in one specific position. I'm 6'3" and have no problem with a TN Solar 2.2, the semi geodesic design means the poles cross at the ends so even touching the inner there won't bring it into contact with the outer, the twin porches mean you can touch the sides without problem. The flattish roof means there's lots of usable head room (though it can gather a bit of a puddle on top) It's promoted as a two person tent, I've no idea where the second is supposed to go, maybe in one of the porches! The more I use it the more I like it, always goes up tight, the massive porch space makes it easy to keep organised without having to bring much into the inner. Although at 2.1 kg a decent weight for the size (Same as the Soulo) the TN doesn’t pack very small and the poles are a bit long to fit well on a rack without overhang.
BUT... much as you seem to have discovered cycling is not about the bike, camping is not about the tent. Before the TN I had a Coleman Epsilon, it wasn't as good, it was OK and at 5 times the price I can't say the TN represents better value. If I had the time for more touring I'd have spent the money on the tour rather than the kit.