Thanks for your reply, squirrel77. What are the ratings for your video card and CPU ?
The system I'm interested in is like yours, except for the i7. I think I will order an i5. Still it would be interesting how the i7 is rated.
In my current Windows 7 system (no Mac, just an ordinary 3-year old desktop PC) that I want to replace, the CPU and RAM are the bottlenecks, with a 5.7 rating

Even my hdd is faster (5.9 as well).
It's reassuring to know that the 5400 rpm hdd in the 17" is as fast as my new 640 GB Western Digital hdd in my desktop PC...