Being a glutton for punishment, I just ordered the latest MacBook Pro 17" 2.5GHz.
My March 2011 MacBook Pro had problems, so I returned it, limping along with a 13" MacBook Pro (not bad at all), and a MacBook Air 13" 1.7 GHz (slow as mud compared to the 13" MacBook Pro, and barely tolerable for what I needed it for, it’s for sale).
I hope this new October 2011 MacBook Pro revision has appropriate motherboard fixes to rule out SATA 6G problems. That I shall soon see (early next week).
I will be installing 16GB of OWC memory, and a 240GB OWC 6G SSD in the 17" MacBook Pro. As I ordered the Apple 128GB SSD, I might use this as the boot drive in the optical bay, using the OWC Data Doubler bracket (because boot drive speed does not matter at all for my files on the 6G drive, and it’s fast enough for system/apps, and then I can dedicate the fast 6G port to a 240GB OWC SSD).