Re: Thick single ply heads?
Big fan of the thicker but single play heads(for sound - durability is just a bonus for the bashers, which I am not). There are less high frequencies in the thicker heads. Just do the tap test on unmounted heads. A single ply 10mil head will sound more "papery" than an Evans G14, and an Evans 2 ply head like a G2 will also sound less deep and w/ a shorter note. You really get the best of both worlds IMHO w/ thicker head, yet single ply.
To prove my fandom, on 14" & 16" floor tom (2007 starclassic bubinga) I run clear G14 batter over clear G14 as resos - smooth, deep tone w/ plenty of life (plenty! - even w/ diecast hoops), on the 10" and 12" rack toms, Evans clear G12's over clear G12's. Granted only 2 mils thicker than a G1 but when you combine the 2, you get the boost in less high frequencies. On the 8"(currently shipping) I will run clear G1 over clear G1. If they passed a law and I could only run one head thickness on the kit, I guess I would go w/ all G12's, but I do think the G14's could pull it off on the entire kit - they resonate well...
I also have now become a recent fan of coated G14 on snare. Really compliments the bubinga 6.5" deep snare. Adds a "thickness" or more substantial presence when hit. I have it right next to a Tama S.L.P. "Vintage Steel" w/ a coated G1. The G1 is thinner and yes, sounds "thinner" - not bad, just doesn't have the presence and "balls", if you will, of the G14. I forever thought one should generally stick w/ the classic single ply 10mil on snare drums... nope, coated G14 is now me head of choice on my snare. Snares are a unique beast in that the batter is so radically different from the reso - a G14 just adds to that contrast(desirable) and the tone of the drum. Speaking of tone of the drum, I've also recently got religion on 12 strand snares (20 is even overkill!) from Puresound. I can see now why Gavin Harrison runs a mere 8 strands!
Hope this helps on your thick single ply question. Answer: yes, even on resos!!
P.S. I also chose the GMAD (I would've bought a 14mil if they offered it - I bet they will sooner than later, eh "Evans Specialist"? It only makes sense) over the EMAD and EQ4... yep thicker, but not for durability but for sound (you can easily hear it on the evans sound samples on their site)