[PD] Windows low latency first-hand experiences?

[Matteo Sisti Sette]

Hi,

I've already browsed the archives and found some helpful information 
about getting low latency in Windows with PD.

Now i'd love to hear about anyone who has been able to get as low as 
15-20ms latency in Windows using PD, without getting glitches, 
preferably in Vista and with external hardware, such as USB or firewire 
cards.
[not that I prefer Vista over XP, but I just happen to have it installed 
on my new laptop, so if I can get what I need without installing another 
OS it would be better for me]

I guess I should go for ASIO4ALL and I want to buy an external audio 
interface, so I was wondering for example if there is any reason for 
preferring usb vs firewire or viceversa; if any audio interface in 
particular has proven to work well (or bad so that I avoid buying it) 
for this purpose; if asio4all performs equally well with external 
hardware as with built-in hardware......

Any positive or negative experience is welcome; a positive 
easy-to-reproduce experience is what I'm looking for.

Also, if the same can be achieved with some relatively-newbie-friendly 
almost-out-of-the-box GNU/Linux distribution, it may be worth trying...

Thanks in advance
m.