Slidouts

The answer depends,,,, here is a breakdown.
You tube

Well.... they both run off electricity and Having had both I saw no difference in them.
If electricity isn't available most gear operated slide outs can be hand cranked in/out.
Some not all hyd units can have a bolt or some way in the hyd pump too allow moving in/out if electricity isn't available.

What’s a bit more important is who makes the slide mechanism, and did the RV manufacturer do a good job installing them.

The provision to hand crank in and out is far more important than equipment type IMO.

Not a fan of cable slides here in the heat if they use plastic cable pulleys. Guess I am not a fan of schwintek slides, either.....
Curly

I've had rack & pinion slides on 3 different trailers for 111-12 years. None ever gave me an issue. I think it's the most reliable slide type made.
Hydraulic will add more $$ to the price of the RV. Never owned an hydraulic slide so can't comment on reliability.

They are all electric but different mechanics:
- Hydraulic
- Worm Gear
- Cables
- Schwintec (?)

Personally, like the worm gear ones.

Have a '98 HH with 3 hydraulic slides, no slide issues yet, I have changed fluid a couple of time and no leaks so far.

Jim

our Newmar Mountain Aire has a total mechanical slide out.. driven by a single electric motor, in 22 years it has never failed.

I have had the fewest problems with a good hydraulic system. Schwintek and cable slides are a PITA.

Ken