I’ve played with the previous 2019 and present CX 200 line up - Tour, “standard” and LS. I really couldn’t honestly say that the Flexbooster tech made any noticeable difference. If anything, I felt that the current line is a tad firmer than the 2019 line.
The CX 200 Tour 16x19 is an excellent racquet. Plush feel in the sweet zone (with nicely tuned acoustics - thanks, BASF), good precision and a controlled launch angle which will suit a high level intermediate to advanced player. Needs a fair bit of lead to the hoop if you like your swingweight in the 325+ range. My only criticism of it is the slightly thin, hollow feel outside the sweet zone. This seems a common trait across the entire CX 200 range, and interestingly, is also present in my Dunlop squash racquets.
I wouldn’t pay the extra for the 2021 racquet, especially when the 2019 version is so similar and is currently being sold at a nicely discounted price in the UK.