Long time Aerial owner here (Model 9s, LR5s, and SW12s) but not the 10Ts. The house sound IMO is dynamic, tonally rich, and well-rounded, and they seem to play well with a variety of music. One of the main differences between models is how they implement the bass. The 10Ts were known to be very solid if given enough power. I believe the 10Ts were their only speaker to use the Kevlar cone midrange. If you haven't seen it, here is Stereophile's review of the 10T and here is a review Michael Fremer wrote about the LR5s I now own along with two of their SW12 subwoofers.
As said by others, you need to feed them high current amplification to make them sound their best.
The ad you posted shows a high asking price compared to what 10Ts sell for now, even considering the condition and stands. You can decide for yourself but you may want to review previous sale prices and compare with the model iteration and condition by checking out this site, or you could use the bluebook here on Audiogon. These are big, heavy speakers so an in-person pick up would reduce risks of shipping issues and should be worth something to both you and seller.