Slide or no slide is a "personal choice". Both work .
I've owned 3 slideout models and 8 non slide models. I never had any slide issues except for cold air leaking in, but I'm just one owner. MAKE SURE you level the RV before you deploy a slide, otherwise you can crack the siding and rack the framework.
What I found:
When using the heat , propane usage was much less in the non slide RV's and they were warmer, easier to heat . Another reason to have a slide that functions while "IN" , you can close it at night to be warmer with less volume to heat and it seems to seal better.
I would make sure you can use the floorplan with the slide in, just in case it fails and you can't get a repair appt. right away .
( FYI: RV mfg's normally offer a lesser hourly rate to dealers trying to make a repair under warranty. While on the road, finding a shop to accept the terms might be a challenge. This might take more time and you'll need to use the TT in the meantime.)
IMO, it matters where the slide is located and how large it is.
A smaller sofa or dinette slide can be pushed back in by one person if it malfunctions.
I would prefer a hard floor opposed to a carpet under a slide . In the past, I have seen many RV's come into the shop with carpet issues. Today , it looks like the mfg's are getting away from the carpet under the slide where it can rub and tear (sometimes).
Watch your payload using the 1500 truck. My 6000# TT has a 900 plus TW., expect to have more TW than you posted.
A TT that's shorter with a small slide might work better using a 1500 truck or a non slide unit.
Atlee (see his post) and I use the 23RB non slide floorplan that offers the sofa facing the rear large full width bathroom. You don't get that 'closed in feeling' as you would in a side facing sofa or a smaller side bathroom. You also get an island queen bed which is the preferred . If you choose a non slide unit, this floorplan might work for you too. The floorplan is avl., in a few brands and works very well using the 1500 . As already stated , you have to try the floorplan to feel it.
just food for thought: ( i don't see where if this was addressed or not)
How do you plan to use this TT ? at a CG hooked up or boondocking with no hookups.
Reason being , If the floorplan has a fridge in the slide, then the fridge will be vented through the slide wall and NOT the roof. This could mean having a 12v exhaust cooling fan to overcome the bends in the exhaust sidewall vent tube . That 12v fan will run off the battery using your stored battery power if you are not hooked up to an electrical pedestal. You can also hear the fan running. Will that apply to you ?
Slide models prohibits the movement of towing it 'IF' it should fail and get stuck in the deployed position.
Common sense tells me to learn the mechanics of the slide involved. Just in case you do have a problem, you won't be stuck somewhere with a slide deployed and not knowing how to retract it in order to tow it.
Know the location of Fuses/breakers and how to align it if it should become loose from travel and bind , then you would not be able to do a manual override with a hand-crank and maybe not be able to force it back in.
