I have a bedroom slide on the passenger side and a couch/dining table slide on the drivers slide on my bath and a half 36 foot coach.
One of the things we really like is the fact that we can use the bathroom with both slides closed and actually the whole coach with both slides closed if need be.
There are times at a very few campgrounds where you can't open one slide or the other so it's nice to have some flexibility in your slide extending options.
Also toppers on a slide are really nice in hot climates, they make a big difference on the inside temperatures.
Our bedroom Power Gear slide mechanism broke a tooth off of the drive gear and was fairly simple to repair as it is located under our lift-up bed mattress.
I have seen problems reported with kitchen slides, usually with the flexible drain system but they are usually quickly resolved.