So far not too laggy, but have only started using it. I feel a bit clumsy using it right now, as no more scroll wheel and missing a few hardware buttons compared to the TyTNII. I relied on those buttons as shortcut keys. Having said that I think I am getting into the rythym of using the Pro
I bought the phone for $HK6280 at Wilson minus about $HK1000 worth of Visa bonus points :). They gave me a 4GB card and the obligatory screen saver. I have the English version of WM6.
I am still with Smartone-Vodafone. Have not tried One2Free before.
I have recently changed to a $256 Smartone-Vodafone plan. I suggest you look into that. You will still get your 100mb data, but you will also have unlimited browsing on the default browser of your phone. You will get 1000min voice minutes as well.
I think the Opera Mobile browser is the default browser on the Pro and so far I have been very happy using it. Much nicer than PIE and pretty fast as well. I love the way it reformats the text to the screen as you zoom in. No need to scroll sideways as you read!!