In many respects, the flex 3000 is a better radio then the 7300.
Lower built in noise level, better audio, better display and a better antenna tuna.
The 7300 can have issues, I had a power issue with my first one, HRO replaced it on the spot, the 2nd one had the screen processor fail, I have a new one I just got that is fine so far.
Easy to use and good for the money sums the 7300 up, poor audio, lots of built in noise, turn the RF gain down and turn the volume up half way, where does that racket come from?
The AGC brings up the band noise between signals a LOT, the tuner is very limits, the screen abd buttons on it are on the small side of things.
I think the 7300 would be great in a car/truck, surface mount stuff tends to be rugged and I think he radio would be fine.
The 7610 is more of the same, all the same issues but a bigger screen and 2nd RX.
With a decent desktop computer, the Flex 3000 is a great rag chew rig.
Its also easy to work on and repairable.