Michael
I use Air wire with Phoenix sound and NiMH batteries (will switch to lithium as the old bats need replacing). I chose this combo as Revo did not exist at the time, other options were LocoLink and Sierra sound or the old LGB DCC system.
I have both AWG90XX, G-2 and G-3 (the new drop ins are all G-3 based) All with external antennas. The G-3 are the current board and can be programmed from the T-5000 (no need to go inside the loco like the older boards)
All of my sound cards are P-5 Big sounds and P-8. I buy mine from RLD. Ronnie will program whatever sound suite you want but if you need to, you can do that yourself with a dongle and some software. Have to pay extra for those.
Throttles are all T-9000s and one T-5000. I know from vast experience with other club members that my T-9000 have better range and control but they are out of production. I do not think you will have any complaints about the T-5000 unless, as has been pointed out, you are running on Andy’s layout…which requires a telescope to keep eyes on your train.
I am not a electronics guy like Eric and Greg. They can give you volumes of technical advise. If you are one of them then you should base your decision on the specs. However if you are like me (monkey with a screwdriver and a dream) I can offer only this example. Without any outside help I was able to install and program the Airwire and Phoenix systems using only the directions that came with the boards. In ten years none have failed me. This is not true of my compatriots in NMGR using other systems, but I believe their problems are a combination of user error and products that are out of production or severely technically out dated and not a design deficiency from the maker. This includes Revo II. Basically, if I can install and program these than anyone can.
Here is a couple of pics on how I did it on different locos. The long version is here: https://cibolalmrr.com/engines/
I suggest you go to both manufacturers websites and download the user manual and see if one fits your confidence level for installation / programming, maintenance and trouble shooting better than the other. Performance is about the same and dollars also include how much of the work can you do for yourself and the helpfulness of customer service. So decide between the two systems what is your frustration level for making trains go.