I have seatcraft adonis seats that I actually bought off theaterseatstore.com year before last. They are very comfortable, look very nice, and have held up great. I love mine. Can't speak to the diamante specifically, but my Seatcraft chairs I love and don't regret the purchase at all. Especially seeing as many other seats were ridiculously priced solely because of the niche "theater" seat moniker. Don't overpay is my advice.
BenQ HT1085ST|Epson 5040UB|Silver Ticket 106'' Screen| Onkyo TX-NR3030| SVS Ultra Towers| SVS Ultra Center| SVS Ultra Surrounds| SVS Ultra Bookshelves| Def-Tech DI-8R in-ceiling speakers| PSA XS30SE subs| Buttkickers X's 4, 2 buttkicker amps| Oppo UDP-203| Darbee Darblet 5000| Monster HTS 5000 MKII| Carver 705x| PS4 w/VR|Xbox 360|Xbox One Forza Edition|Xbox w/coinops| Harmony Touch| Dell XPS 420 HTPC W/ Kodi W/12TB NAS| Seatcraft Adonis Seats| Monoprice & Sewell Direct cables|OmniMount RE42 Rack