My first pair of riggers were Scotty manuals with extendable boom and swivel base. The ext boom and base gave me a lot more options as far as installation placement went as well as a lot more versatility when it came to running different rod configurations. I went with the Scottys because of the 2 ft retrieve per turn which sure was nice when fishing deep and the clutch system for dropping the weight. Turns out they were pretty much bullet proof and I was glad I went with the Scottys.
As happy as I was with them I sure was a lot happier when I upgraded to the electrics. LOL Good luck with your decision.