Most rigs have a slide now, and everyone that has a slide seems to love them. Personally I didn't care much either way, my criteria being everything needed to be usable and accessible with slides closed (I hate those motorhomes where the bed has to be folded in half to retract the slide! How is wife going to sleep in the morning while we're cruising down the road?
I ended up with a good deal on a non-slide rig (buying used), and have no regrets. My in laws have a sweet class A with three slides and it does feel like a condo compared to our tunnel, but they also paid 5x...
I'd take a slide, but I'm perfectly happy without one.