There's no real performance advantage to using either over the other for most cartridges.
For the few applicable cartridges that I load, I choose what's available - and that's usually XTPs.
But, for .480 Ruger and .475 Tremor, it's the opposite. I can almost never find the XTPs in stock when I want them, but often run across good deals on the Deep Curls and/or find them in stock when I need/want more.
So, it seems to be the opposite of your situation. I've 'standardized' and settled on Deep Curls because that's what I can get and get good deals on. But if XTPs were more available, I'd probably use them instead. (The nose shape would be easier to feed in the .475 Tremor, too.)
I will say, though... The XTPs are always clean, pretty, and in good shape in their bag-in-a-box. The Deep Curls are always filthy, ugly, and dinged up.