Ah slides, love them or hate them just about everyone has an (often strong), opinion. Some folks simply can't live without them and others like myself have no use for them.
On a 30' Class C (that the OP is contemplating). The issue of weight will need to be addressed.
A 30 footer with more than one or one of the huge full wall slides is going to seriously cut into the coach's payload often leaving little for bodies and gear. Weighing any such coach at all four corners would be essential as not all manufacturers manage to balance the loads.
We have a a 24' wide body Class C with a floorpan we love (101"wide with 7' of headroom throughout the coach). We don't have grandchildren and I can't remember the last time we were forced indoors for the day by weather. We just have no need for a slide and thus will never incur any of the many issues that can arise. Hardly a day goes by on this and other RV Forums without someone documenting slide failures/problems, it happens {a lot}.
Best to honestly evaluate how you will actually use any prospective coach and make the slide/no slide decision rationally. Ignore the nonsense that you will not be able to sell a slideless motorhome, evaluate the consequences of the additional weight and be prepared to deal with the issues of leaks and potential mechanical failures.
Consider accessibility when the slides are closed as well as your maintenance access. The folks who regularly use/maintain their slides seem to have the fewest issues. Naturally the higher quality motorhome will have better slide(s) as you still tend to get what you pay for.
As always.... Opinions and YMMV.
:C