Hi Kevin
On the plus side the Alumilite is easy to mix (equal parts), is fast , you can start your project about an hour after you mix it , turns very nicly and has no real smell.
On the minus side It's expensive about twice the price of PR and I dont like the way it final sands . It shines but not as nicly as PR , to get that REAL PLASTIC

shine you gotta CA it .
The PR on the other hand is Cheap (Acrylic slimlines are now cost effective

) it's very easy to sand and finish and has that REAL PLASTIC

shine.
The downside is the smell , which I happen to like , it does have a strong smell ,
and the mix is X number of drops of hardner per ounce of resin which varies with temperature and colorants (dyes,perls,pigments,micas) and from what I've read also on the thickness of the casting . Also you should let it cure overnight
As for coloring , anything you can use to color alumilite you can also use on PR including powder coat paints