Definitely don't use it for dry trimming. That is what will 'destroy' the weed... you'll lose more bits of bud and significantly more loss of brittle, dry trichomes compared to wet buds. It might look better, but definitely wasting more bud and knocking off more trichomes doing a dry trim.
There's not much of a quality difference betwen then, so let price point guide you. Silicone 'fingers' dragging/flipping the buds and a blade spinning around does not entail significant differences in product quality. It's not a tool of precision. The trim will not be close but isn't too bad. If you have high expectations, expect to be disappointed by these devices.
Size is an important factor. Diamter increase is a signficant effect. e.g. a 24" diameter has roughly 2x more space than a 18".
12^2 x pi = 452 in^2
9^2 x pi = 254 in^2
If you do small plants, no big deal, but if you grow at any scale, consider finding a well-priced 24" variety or even larger. Twice the capcity for a a few dollars more is a good deal. I found a 24" for 180 dollars a few years ago.
Fwiw, i do not use this thing anymore, lol. It collects dust in my crawlspace.
They do an okay job. It just isn't worth the hassle to clean and store etc.. Cleaning that wire grate and the blades make the time saved trimming minimal, imo.