I did/do have a spare, which was in the rear storage compartment (part of why I pursued getting the carrier ... wanted that space back). As for discount, I will ALWAYS buy my tires there. We've taken 2 trips cross-country (one of them with our other camper which was a Damon Camplite 2408SLE -a tandem axle popup). Both trips were fraught with tire problems and both had Discount Tire "stepping up". I'll try to give the Reader's Digest version here (hijacking my own thread)...
Trip 1 (the one with the camper). I did not ensure everything was 100% before leaving. We're driving trough PA and have flat on the tow vehicle, on a Saturday. Luckily, we were within 10 miles of a tire shop that was open on a Saturday and were able to get back on the road. The camper and Tow Vehicle were packed full (3 week trip, 7 people) and so we did not have a place to carry the old tire. After visiting friends in NYC, we headed to Buffalo and were pulled over by State Police because our trailer did not have tags. (They must have "fallen" off ;-) ). Upon doing his inspection, he noticed that one of my tires on the camper was missing a fair size chunk of tread. Again, luckily we were very close to a tire shop that was willing to mount my spare and we were back on the road. The officer also noticed that the front tires on my TV were looking more like racing slicks (than passenger tires). There weren't but a few national retailers in Buffalo and the ones that were there did not have tires to fit my trailer, so I opted to try and make it to the closest Discount Tire in Hilliard, OH. I called them in advance and they said they would have the tires ready to go and would get us in and out as quick as possible. They also asked us to keep them apprised of our progress so that they could put us in the schedule based on when we would get there. I did and they did. They dedicated 5 technicians to the job and replaced 9 tires (4 on the van and 5 on the trailer -including the spare). We were in and out in 45 minutes. Plus, because I buy the certificates, they only charged me for 7 tires. The certificates covered the tire we purchased in PA (though I was not able to produce the original tire) and the trailer tire that was missing a chunk of the tread, even though the DOT stamp showed the tire was over 5 years old.
Trip 2. Same trip, no camper. We survived the whole trip (almost). On our way home, through New Mexico, we got a flat. I changed it and put the spare on, but, by that time (Saturday evening) there wasn't a tire shop open near by, so after weighing our options, we decided to press on through to our destination for the night. Wouldn't you know it... 40 miles east of Albuquerque, we had another flat. After getting insurance to send a truck and accepting a ride (for half our troop) from a good Samaritan (who only after we were already on the road admitted that he had just been released from prison for kidnapping!), we made it to alb. It turns out the Pep Boys that we dropped the truck off at was less than a mile from our existing hotel reservation. Pep Boys replaced the tires (they're open Sunday) and on Monday (at home), I had Discount put the correct tires (brand etc) on the van to replace the tires PB had installed. They refunded the purchase price of the PB tires and all I had to do was pay to put certs on my new tires.
Most recently, My daughter (who is a younger driver) hit the curb in that same van and blew out both passenger tires. I took them back to discount and they replaced them (only costing my the price of new certificates).
I will be a Discount Tire customer for life.