You will likely get differing views on the slide issue. A suggestion I have for you, is to think how you will mostly use your RV. If you go to a place and camp for a weekend or week, and don't plan to move, a slide can make sense. If you like traveling the highways, and only spend a night or two in one place, they may not be as beneficial. If when camping, you think you will spend a lot of time outside the RV (hiking, fishing, etc.), you will not benefit as much from a slide, vs. being inside the RV. Remember, the slide is in while moving, no additional room then. Further, if you like to boondock in Forests or out of the way places where room can be tight, you will need to make sure you have the room to deploy the slide. Most commercial CGs will not present this problem. Finally, slides add weight and decrease the Cargo Carrying Capacity of the chassis. You will need to take into consideration how many people and how much stuff you plan to take with you on your trips (as with any RV).
Wishing you success with your purchase. Bob