Hello and welcome to the forum
I own a T42 15" SXGA+ and I currently have a 14" Z60t & 15.4" WSXGA+ Z60m in my possession for review.
The Z60m is a lot larger than 14" T-series, and a fair amount larger than a 15" T-series. The biggest thing you'll notice is the thickness and length. This is not supposed to be as petite as a T-series, so if you're really stuck on the size of the T's I don't recommend a Z60m.
That said: the build quality is awesome, it is very sturdy and solid feeling. While it does weigh 7.3lbs with 9-cell, it doesn't feel very heavy to me. I'm a college student and taking this around campus in my laptop backpack wasn't bad at all.
The 128MB X600 can play Half Life 2 at 1680x1050 pretty decently. It was a little sluggish, but I bet if you used Omega drives and/or OC the GPU you'll get some nice frame rates.
As far as the hard drive goes, you have two options. First, you can go for the 80-100GB 5400RPM. These drives are still very fast and the higher areal densities of new drives help make up for the spindle speed. Also, sometimes Lenovo uses a Toshiba 5400RPM with 16MB cache; the larger cache on these drives also helps with performance (esp game load times). Otherwise they generally use the Hitachi 5K100 series. I recently did a 2.5" drive roundup and you can see the results here:
http://www.laptoplogic.com/reviews/detail.php?id=92
Now since the Z-series uses native Serial ATA drives, you will need to pick up a SATA drive instead of the standard IDE drives. Seagate, Hitachi, and Toshiba all have SATA drives; Seagate & Hitachi have high capacity 7200RPM's.
If you want the 7200RPM speed, I'd get the minimum drive size w/your unit and add-in your own 80-100GB 7200RPM.
I will have my complete review posted by the end of this week, full of pics & benchies
