The concept has been around for ages - heck its in the into to Small Soldiers. That said early reviews of the Rocket 1 are not favourable
https://www.youtube.com/watch?v=QhIPzHfb-Ts
Even the big speed increase over other regular LCD printers isn't that great a gain and their "super fast times" are quoted for 0.1mm thick layers (which is basically not valid for most who print at 0.05mm at the thickest).
If you watch the video he highlights that one of its biggest issues is mess - the Rocket 1 has design aspects which result in spilled resin all over the place. It's a lot of mess and this is in the hands of someone who is pretty experienced in 3D printing, so even if you can "tame" the printer its clearly not user friendly.
For me the other big limit is as Valander notes - the need for a big resin vat full of resin to get started. The Rocket 1 has a capacity that takes up to 3.75litres of resin. That's basically 4 bottles of resin and then you've got 0.25l to print with before you need a 5th bottle. That's a big up front cost.
They do say they've got a "filler" chemical which basically settles underneath the resin, however that doesn't sound good to me either as that binds you to a specific print height and if you want to change it you've got a lot of mess faffing around changing out two liquids (likely losing a portion of both in the process) to change the ratios.
Then if you want to play with another resin for a single print - yep - its either a second big vat and a lot of resin or another hassle and mess draining a very heavy vat.
Overall the idea of having no
FEP pull is great, it means reduced pressure on the supports as the only weight is the weight of the model so you really could get away with lighter and fewer supports for even more perfect model printing. And it does seem to print well.
However for me I would want that printer. It's just not practical. Basically 5 litres of resin to get printing; all the potential mess; all the increased faff of dealing with such a big VAT.
Even if they resolve the mess issues, I think printers like that would need resin prices to come way way down to be viable for home printing.