I own, use and enjoy software from Adobe, DxO, Topaz and Tony Kuyper - all represent good value and I'm happy to keep them updated to the latest versions to benefit from any new features. Having said that, everyone likes to feel they've had a deal, so I do look to take advantage of their offers/ sales.
(I'm not one of those people who expect them to continue to develop and fully support software for all eternity because I bought a copy back in 1991. I want the companies to be strong, successful, innovate, pay their engineers and staff well - and produce great software I can have the pleasure of using).
Topaz PAI has some very worthwhile features, if used appropriately and with due care. The 'Auto Pilot' function has always been completely useless (IMHO). I really like using their - now discontinued - Studio 2, which as well as being a creative powerhouse, was also a hub for their other photographic apps.
Phil