I honestly cannot say i care if the game costs 10 a month, 25 a month or 40 a month. I have enough disposable income that i can say "Yeah, i like this product and i'm willing to pay to play it". And i think the "pay-wall" is an excellent wall. It does weed out people who aren't that serious about a game, though i think it important to have some kind of trial or free portion at SOME point to interest new players.
But, in the end, i'm a big fan of the monthly subscription model, and i think you guys chose the right thing in going for a model like that. Cater to your audience, right? And your audience, people like me, consist of people more than willing to pay a monthly fee for an experience like this.
I'm sure this has been said before - just throwing my old opinion into the ring :).