How much does it weigh? 105 R7000 is like 220g. Does it weigh more than that? If that's the case, I'd probably just use Shimano components.
My R9 weighed in at 229. I think the RX quoted at 219, which I believe given that it's kitted with lighter parts like the B-hanger screw. I did the math on the system weight of the LTWOO RX vs Shimano 105 11s and the RX is supposedly ~50g lighter for brifters, derailleurs, and calipers.
Given what 11 speed 105 groupsets are going for, I would not pay more than $400 inc. shipping for the RX system. It also depends on availability, 105 group-sets typically force you to buy the crank, cassette, rotors, and chain in the bundle. By going with LTWOO, I was able to spec fancy rotors, power-meter crank, and cassette
It's a shame they don't sell the shifters separately. They are substantially lighter than Shimano 105. And I get the feeling that they are compatible with Shimano derailleurs since previous, identical-looking generations of the R9 were marketed as such.
In an ideal future, I would love to try: LTWOO shifters, |||PRO/ONIRII "XG" hope-knockoff calipers (96g), Shimano 105 front mech, Shimano ultegra/DA rear mech.