This is my 3rd recent pair of Puma shoes, and a 4th pair is on the way. I used to wear Puma many years ago (late 70s),and loved 'em then too.

I have two pair of Faas 550, and I love them.  I bought this pair of Faas 500 on a hunch that I would like them too, and I was right.  They are super light weight.  Cushioning is like running on air!  Midsole is soft.  Puma has it right.  Other shoes tend to have too hard of a midsole.  Like my other Pumas, these have little to no arch support, and that doesn't bother me.  I am a neutral fit, normal arch.  There is no heel support in the back of the shoe, and that feels great.  Right out of the box I could fold the heel down into the shoe.  Very little (minimal) support on the sides.  I am not an expert on categorizing shoes, but these have to be somewhere in the minimalist category... and that's what I wanted.  I ran 5 miles on the treadmill as soon as I opened them.  These, and my Faas 550s are so good, that I had the confidence to order a pair of Bolt Faas 400s. (they are on the way)

I usually wear size 8 1/2 shoes, and I wear size 9s to run.  Based on that, I would say that these run true to size.  I haven't tried any Puma in 8 1/2, because I ordered online and got 9s on the first try.  As runners know, your feet swell when you run, so you should run in shoes that are slightly big on you when your feet are cold.  It's possible that I could run in a 9 1/2 in some shoes (such as Asics), but Puma 9s are perfect for me when running.

I bought this pair on clearance.  The color wasn't my first choice at all, but it turned out that I love the color too.  I can't imagine how much I would love these shoes if I bought my first choice colors!  It would be off the charts!

UPDATE - I wore them outside on day 2, for a 10 mile street run in cold, wet weather, the shoes got dirty, and spots from gross road dirt (who knows what was in the dirt - oil??)  I cleaned my shoes by hand, then sprayed and presoaked, and finally put in the washing machine. The spots and streaks on the inside of the mesh above the toes still did not come out completely.  Moral of the story, don't wear these (or any other light colored shoes) in wet dirty (street dirt) conditions. I still love the shoes.