If you are considering purchasing, go for it if it makes financial sense for you. Amazing vehicle for the price. Kia's powertrain warranty is up to 100k miles, so you're covered there for at least 5. Your warranty may run out on some other components, and you could always buy an extended warranty - (see
@Jason Fox for a good value there). We previously had a Kia Soul through 78,000+ miles - NO major issues - it was a very reliable car. As for the Telluride, it's too soon to determine reliability, but judging by recent evidence of Hyundai and Kia's initial quality rankings and other rankings, I'm not too concerned. Plus, anything that does go wrong with a Kia is usually a lot less expensive to fix than a luxury vehicle like the Q5. Regular maintenance like oil changes, alignments, wheel balancing etc will also be less expensive. It drives much better than a Honda Pilot, and frankly you should be excited about the Telluride - both exterior and interior style. Very well appointed for the price.
If you want to know what problems folks have had, they are throughout this website. There have been complaints about cracking windshields (they are acoustic laminated glass, so probably more prone to cracking than older, non-laminated glass, heavier windshields. There are some complaints of vibration detected in some AWD models (I think this could be due to a transportation issue, as multiple cases appeared at same dealerships / regions). Other issues have been relatively minor, but in most all cases that I've read about on here, Kia has resolved or is resolving the issues through dealership service departments.
I wouldn't focus on the problems - as Kia has now built and sold around 40,000 of these vehicles this year, and we've only seen a handful of issues on this forum and others. People are comparing certain trims to high-end luxury vehicles - which isn't entirely off-base, but also not the target competition. This vehicle competes in a crowded market against the mass-market targeted Dodge Durango, Honda Pilot, Mazda CX-9, Nissan Pathfinder, Toyota Highlander, Volkswagen Atlas, Subaru Ascent, Chevrolet Traverse, Ford Explorer (certain trims), GMC Acadia, Buick Enclave, and their sister company's own
Hyundai Palisade. I think the SX trim can compete with offerings from middle luxury Acura MDX or Infiniti QX-60, and the SX Prestige could potentially compete with certain trims of the Q7 (2.0), the Volvo XC90 (base engine) or the Cadillac XT6 (each of those has far more powerful engine options, as does the Explorer.)
Right now there is a Telluride premium - in the sense that inventory is tight, and they are priced at or above MSRP, and KMF (Kia Motor Finance) incentives are dwindling away each month. Given how much you drive, it may not make sense to purchase a Telluride right now if you don't NEED an adult-sized 3rd row. There are lots of deals on some of those other models mentioned that may make more financial sense - and then look into the Telluride in 3 years after you have put 60k on the other vehicle and the warranty is up. If you need cargo volume, and an adult sized 3rd row the Traverse or the Atlas might be a good choice. The Ascent also perhaps - check out transmission issues. Can't really go wrong with a 2019 Highlander - but also can't get too excited. Maybe the 2020 model - but then there won't be discounts on that for a while. Same story with the Ford Explorer. If you need to tow a lot, then the Telluride may also not be the best option.
I did purchase and take delivery of an SX Prestige and couldn't be happier - but we did get $2500 off MSRP via KMF rebates, we don't drive a lot, and we plan to keep the car for 10+ years - unless reliability becomes a problem for some reason! No one would fault you for choosing the Telluride! And if you do choose it - find a dealer who will order at or below MSRP and agree on price up front. There are plenty that will.