Since this is a newer shoe and I have only found one review on it I thought I'd share about it.  I bought these somewhere else at a fantastic price because the tiny sizes were on sale.  I'm a girl who wears a Nike running shoe size Ladies 7 and usually a Euro 37.  I bought these in a 6/Euro 39 and am happy so far.  I don't know if I could go down any smaller because these don't come any smaller.

I only wear these for indoor climbing and have only owned them two weeks.  The reason I chose them is because they are really, really stiff and I'm short so the stiffness helps me stick a foot that's way out there (for someone with short legs like me).  I can literally stand on the tips of the shoes like a ballet dancer in pointe shoes and they don't bend.  This comes in handy when I belay someone heavier than me who falls off the wall or needs a little extra oomph up the wall.  I still have contact with the floor and am able to help better.

I chose the lace up style because the laces and placard that the holes go through help made the shoes stiffer on the top too.  Moccasins are just too flexible for me and I don't like not being able to adjust the toes at all.  I'm able to keep the laces loose through the first three holes at the toes and then tighten as I get to the top of my foot.  The laces are the lumpy bumpy style which makes them a pain the first time you lace them unless you carefully work the lumps and bumps through the holes--otherwise they bunch up and you have to wiggle everything back through.  The lumps and bumps excel at helping you spot tighten the shoes if there's just one or two areas you really need the shoe tight.

I've only been climbing/bouldering since May and climb indoors 2 - 4 days a week.  I feel more confident in these shoes because I can predict how they'll respond better than the rental shoes since every climb was with a different pair and socks (I was not going to put my bare feet in rental shoes!).

These shoes are leather and lined with a moisture wicking material (so 5.10 says, my feet still sweat in them but I only notice when I'm on the ground, it doesn't bother me when climbing).  On their box it says lined leather shoes will stretch about 1/3 of a size.  Every time I put these on I think they're too small and after about 5 minutes I fall in love with them again.  I'm not sure if they're worth $150, but I only paid $90 and I'm very happy.  They seem to be the only high performance shoe of this style out right now (they have the Stealth Onyxx soles).

Final deal closer for me was that they are Made in the USA!