I use the Zimo MX645 on my LGB rail truck, and I pull several cars. Wire version is $85 (1.2 amps) and P22 version is $100 (1.8 amps).
I added a Kadee coupler and ‘chained’ it to a servo and can do remote uncoupling.
Remote volume control is also on these decoders.
Specs are 3 watt audio, can operate 2 servos, can witstand 2.5 amp surge, more than 40 volt surge.
This is an HO decoder but has specs that exceed G scale standards. (NMRA is 22 volts DCC and 27 volts DC, Zimo spec is 30 volts)
There is a free software download for the sound (Oliver zoffi), and there is a ‘lode Code’ at $25 for the decoder to load the different galloping goose sounds from H. Dappen.
I used the free sound and it runs through the gears and has a motor startup sound and ‘floating’ valve sound.
I even use the P22 version on the LGB stainz locos.
My only issue is there is only 1 input sensor on this decoder, but I find the motor speed via Bemf works great. THe newer but not yet available MS decoder should have 2 inputs.