Before we bought our '07 ROO HTT, DH was absolutely, positively NOT gonna have a slide. "More weight and just one more thing to go wrong". We decided on a 19 and ordered it. FR was busy making 21SS and 23SS HTT as fast as they could, and our 19 had several option items. 4 months later we still didn't have it, so contacted our dealer and told him we'd be in the area on Saturday and needed to leave there with a trailer or needed our deposit refunded. Long story short, we left with a 23SS.....as in Super Slide. Both the kitchen and the sofa were in the slide. We loved it and never had one minute's problem with it. Our camping buddies bought a Shamrock 19 and when we camped together, guess where we headed to play cards or dominoes or just "be". Add into the mix an 80# lab and their 35# cocker and when we were in their 19 it was just a bit too snug for comfort. There was never a day we were sorry that we didn't have the 19. We recently made the change to a TT and it also has a good sized slide and it's wonderful. wmoses.....you're having too much fun in that new TT!
Re resale....I think it would certainly be a benefit and you would recoup your money in a hurry, not to mention appealing to a larger market.
Maintenance is not a difficult thing. Keep the slides lubed, clean and condition your seals, check the mechanism from time to time and absolutely, positively have a slide awning. With just the awning, you eliminate all the leaves and junk falling on the slide top, minimize chances of water when you close up and it's just something you need as a part of the awning.
Personal opinion is that you would be sorry very quickly if you chose not to have a slide. Amazing how much roomier it is with just that amount of extra space.
Re bathroom/kitchen access when traveling....it's nice to have and don't know that it would be a deal breaker for us, but as it happens both our ROO and now our Rockwood Ultra Lite have access. With the '07 ROO, they highly recommended the use of the slide locks that were provided and we always used them. If we had a model that used them and had to be removed to have bathroom/kitchen access, it would have been a PITA. Not hard to put on and take off, but just a step you wouldn't want to do very often.
Hope you can find a model you like, that works with your towing capacity and budget, has a slide and bathroom/kitchen access. Personal opinion, that would be the best of the best.