I like the deluxe Vader , I don't have the hot toys one in hand , but I do have it on order . But even with the comparison videos I've seen I still like the deluxe . The alt head sculpt is really nice , and as long as I'm not constantly looking for faults it's a nice piece .
That being said , I would also offer the suggestion that you get a trooper and the hot toys Vader , just for better quality , and in the hope that hot toys will make a ROTJ Vader with alt sculpt one day , or even a meditation chamber Vader .
But also again I don't think the Deluxe is a bad choice. The skinny arms and huge gloves bother me personally , but depending how you display him , and keeping in mind that he's not being stared at all the time to nitpick , I'm very happy with him in my collection.
Best advice is to check out multiple YouTube review videos of each figure you want
I will say that when I ordered my first sixth scale last year I was torn between grievous and Vader. I ended up going with the general because the arms and gloves bugged me , but then the next day I went to a toy shop that had one on display and I bought Vader immediately because he looked awesome , and I have never regretted it.