I'm actually really happy with how they feel made out of the Simply Soft... I'll probably make a wool pair eventually, but these are perfect for when it's not-so-cold out (which is really when I'll be wearing them anyway). I added 5 more rows of ribbing after the thumb, and did a standard bind-off instead of the picot, and I'm very glad I did both.
The pattern's method of doing the thumb is weird - I don't know if it's because I've gotten spoiled on gusseted thumbs or what, but it looks and feels like it's sticking out at an uncomfortable angle. It works out ok for me on these because they came out a little too big (yay for not checking gauge! - snort), but if they actually FIT, I don't know if I'd be able to wear them because of the funky thumb.