I went back to 6v after being 12v for several years.
After:
- cleaning all battery cable/strap ends and connection points, and
- applying ant-oxidant copper-impregnated grease, and
- making sure all battery cables and straps are no smaller than 2 gauge (00 gauge on one truck)
I have had no problems for over 14 years.
My 14 year old 6v Optima battery is still going strong.
One problem I had to remedy was/is dim lights from poor grounds where fixture screws/bolts ground where the attach to the body/etc.
I am satisfied with my 6v radio.
If I wanted to add more-modern accessories, I'd change to 12v.