I use a G1 for LACoFD and it preforms very well, no issues or complaints.
To everyone's knowledge LAPD will be staying on their UHF P25 Conventional system for a while. As in the time frame from moving from UHF to 700 mhz its all a matter of time once their whole new system is built out. This could take several years as we have seen with LA-RICS so far with their build out.
As to the Unication radios they are very sensitive and the receive on them are pretty amazing. As for the VHF/700/800 you bought the right radio for your usage. This radio will work very well in Riverside Co for VHF and for Trunking for San Diego. These radio's handle simulcasting very well. You won't have any issues with them. Keep in mind that when you get the radio there is a bit of a learning curve. There is a lot of YouTube videos out there on programming. Make sure you follow them very careful.
Also, Unication is working on a firmware upgrade to be able to have the ability for multi-site trunking
I have the VHF/700/800 radio and performance is amazing for simulcasting with no issues. I really want the 450-512mhz /700/800 radio but just can't afford it right now.
A bit of an update. I received the second Unication, a UHF-D model, and was able to spend a couple of hours in the LA area with it. As expected, it did a very good job with LAPD, LAFD and LA County Fire. I did not try much with LASO, however would imagine it would do great. I did take the VHF model with me as well and programmed Monterey Park's VHF P25 Conventional dispatch channel. It did very well there as well.