I wouldn't want another RV without slides. We have 2, a large one on the curb side with two bunks and the wardrobe and other drawers for the back bedroom. We have had zero issues with this slide other than a minor problem with the carpeting that a few staples fixed.
The other slide is smaller with the stove/oven and couch. This slide will pop a 30A fuse every so often, but haven't been able to figure out why. It is very sporadic and may not happen for months and then it may happen every time we try to move the slide. Only happened once this year.
The added floor space the slide offers for our family of 4 is very nice. We can use everything in our camper with both slides in except the back bedroom's wardrobe and 3 drawers.
The two slides do add a lot of weight, so we run pretty much at GVWR when fully loaded, which translates to an average of 7.5 mpg at 70 mph and about 8.0 at 65 mph.
We camp sometimes up to 4 months at a time (in one campground). Having the extra space is worth the trade off. If we were weekend warriors or only used it a few times a year, it might not be so important.
-Michael