May I offer an alternate opinion on slides...
For me slides offer lots of potential for problems and only one small benefit, that being a little extra room. The bigger the slide the bigger the possible problems. As noted they add weight that comes right off of your OCCC, tend to leak hot air or cold not to mention water. A slide failure is usually a serious problem.
Since the OP is looking at B+/C's that would tend to indicate a smaller coach. Finding a floor plan you can live with is the most important factor and will often eliminate the need for a slide. We spend about 12 hours a day outside of our 24' C and since it is 101" wide with a full 7' of headroom throughout we just don't need one but it is just my bride and I (and hopefully another doggie someday... sigh}.
The OP should consider where and how he will use the coach the most and perhaps the need will not be there. If you travel with kid(s) then the extra space, particularly in areas of frequent inclement weather, that a slide adds may be worth it. For those that have them preventive maintenance is the key to heading off problems.
IMHO: There are two types of slide owners....
Those that have had a problem and those that will.
As always.... Opinions and YMMV.
:C