I still use my Thinkpad x61 as my daily driver (typing on it right now) and I don't feel most of the "severe limitations" you are listing. I think some are wrong (eg. I use Dual-band AC wifi and BT4.0 wifi card in mine, and have a 2.5" SATA-II (3Gbps) SSD), and others are not limitation for my use. I won't recommend it to everyone, mind you, but for my use it is perfect.