Generally speaking, R61i was the less expensive version.
However, you'd have to compare specs of the two examples piece by piece and decide for yourself what suits you better. There were simply too many variations within the model designation
Cheers,
George
A31p (2653-???) P4M 2.5/2GB/250GB, 15" UXGA IPS, XPP/Mint ...the best ThinkPad ever...
T43pSFL (2668-BY8) PM 2.2/2GB/32GB SLC SSD, SATA-modded, 15" LED-AFFS UXGA mod, Win 7/Mint...my best friend...
R60F (0657-???) C2D 2.0/3GB/128GB SSD/ 15" SXGA+ IPS, Win 7...a FrankenPad toy for my twin boys...
T410 (2537-RB7) Core i5 2.4/8GB/128GB SSD/14" WXGA+ TFT, Win 7/Mint...just grabbed by my only daughter...
Z61m (9450-38U) C2D 2.0/4GB/500GB/15.4" WSXGA+ TFT, Win 7...my wife's new best friend...
...plus an iPad 2...and a ToughBook...or two...
I build FrankenPads....scary FrankenPads...
S = SATA-mod (on T43/p units only)
F = FrankenPad
L = LED-mod utilizing an UXGA AFFS LED screen
Please DO NOT PM me with requests for individual support, but post your questions and concerns in the appropriate section of the forum where other users can benefit from them as well. Thank you.