I'm almost pulling the trigger on this specific bike (also at a dirt bike dealer) but I've had experience with mountain biking first before dirt biking. With regular mtb loose uphills have always just been about staying in a gear where you maybe don't spin and just having the right tire, although there's only so much you can truly do with a mtb tire going uphill if you don't have momentum going into it. The main thing is that downhill bikes have horrible geometry for long rides going uphill, so compensating with a motor fixes that issue essentially, whereas if you're manually pedaling you have to make tradeoffs with bike geometry in climbing vs descending. Now you don't have to be in shape like a world cup cross country rider just to pedal back uphill with a bike meant to go downhill and hit huge jumps.
Yeah, good points. This thing is pretty much the perfect all-around bike surprisingly great as a commuter around town and very capable in the mountains.