Speaking with a bit more exprience than I started and on my 3rd camper over the years. The first don't count as that was about 25 years ago. We purchased a Pilgrim 5th wheel about 4 years ago. It only had 1 slide, which we thought at that time was plenty, but we soon found that MORE is better. If you get a double slide, where the kitchen table and usually the couch is over one slide and the other slide is usually part of the living room or entertainment room. If you go with the 3 slide, then the 3rd slide is usually part of the bedroom and the bed is sideways and when the slide is out, you have a LOT of room in the bedroom. Of course there are 4 and 5 slideout trailers, but you have to go BIG to get those, probally in excess of 38 feet. We have a Jayco 37 foot 5th wheel with 3 slides and we really Love it.
There are so many different configurations that it would be impossible to say which design is better.
The slides are DC powered, with a manually crank backup. It don't take much battery to bring them in and out, but I would take a look at your DC monitor and make sure the battery or batteries are charged before heading out on a trip. If you hook the AC power up to the camper, you wouldn't have any problems.
At the start of camping season, I'll usually get underneath and give it a nice once over and lub up the screws on the slides and look for wear. Whenever I'm hooking up the water and AC power and I'm under the ground I'll look for any problems. There isn't a reason to lubricate the screw jacks more than a couple times in a season.
Keep in mind, the more slides you have the more weigh you are pulling. Ensure you have plenty of horses to tow one of these monsters around, which is a completely different discussion. :whistling: