Gamma progression ii 602 vs 602FC vs Pro's Pro challenger 1 - Fixed clamps questions?

Hi Everyone,

I've recently decided that I want to sell my Pro's Pro shuttle express (on sale in the buy/sell) and get a 6 point dropweight machine. Reason being that I found that I miss the string jobs of my old Klippermate m140 as they were more consistent and the machine needed less maintenance.

I'm currently deciding between the Gamma progression II 602FC, Progression 602 (no fixed clamps), and Pro's Pro challenger 1 and I would greatly appreciate some input.

They all appeal to me because they're table top dropweights with a ratchet, however I don't know if the fixed clamps are worth the extra money.

1. Do fixed clamps provide a convenience that warrant the much higher price tag (relative to its non fixed clamp counter part)?
2. What advantages do fixed clamps have over flying clamps?
3. Will the larger turntable/base of the fixed clamp machines translate to a more sturdy/stable turn table vs the progression 602 that has a more narrow bar?
4. How does the quality of the Pro's Pro machine match up against the more expensive Gamma?

Thanks everyone!