Forget about the RT-85 BQ encryption. It doesn't make any sense to spend time on breaking it if you can only buy BS version nowadays.
RT-85 or UV-88 is definitely better. It has better shielding, better filtering, with a separate cavity for the BK4815, and one 6W power amplifier (HTL7G06S006P) per band instead of the single and 2W rated RD02LUS2 transistor used in UV-K5. Case feels way superior as well. The only drawback is they use BK4815 instead, which is only 128-590MHz.
Other options are Retevis RA685 and Abbree AR-F5, using ARM MCU + BK4815.