I disagree that moving from Thiel to Vandersteen will mean "everything will be too dark". I had Thiel 1.6s. I really liked them alot but wanted more bass as they pretty much didn't have any energy below 50 Hz. I considered Thiel 2.4s but decided to go with the Vandersteen 2Ce Sig IIs. IMO, the Vandersteens are better in most ways, with a full, musical sound the Thiels couldn't match albeit the Thiels wer more transparent and, maybe, a smidge more dynamic.
I've never heard the 5s but have heard the Sevens, Quatros, and Thiel 3.7. These were all in different systems/rooms, so I will not offer comparisons. They all are great speakers, however, and there is no way to make a mistake with these choices. The Sevens are a top three all time speaker in my experience. If I could afford the closely-related 5A Carbons, I would get those. I think that Vandersteens, on balance, are a "better", more musical speaker than Thiels. That said, the 3.7 is a great speaker (that also looks much nicer than any Vandersteen) that I could happily live with.
I've never heard the 5s but have heard the Sevens, Quatros, and Thiel 3.7. These were all in different systems/rooms, so I will not offer comparisons. They all are great speakers, however, and there is no way to make a mistake with these choices. The Sevens are a top three all time speaker in my experience. If I could afford the closely-related 5A Carbons, I would get those. I think that Vandersteens, on balance, are a "better", more musical speaker than Thiels. That said, the 3.7 is a great speaker (that also looks much nicer than any Vandersteen) that I could happily live with.