Plus I can't readily get my hands on a Thinkpad (even an SL) to try it out. I want to upgrade my laptops at the moment and would dearly love to walk into the equivalent of the Apple store, sit down, and try out each of the models that I'm interested in - but in London there are only a handful of retailers that stock Thinkpads, fewer that are up-to-date with the models that they sell, and none that I know of that have demo machines in store for any significant fraction of the range.
So if I want to buy one I essentially have to be willing to accept delivery (a pain when I can't predict where I'll be on any given day), and willing to risk buying a machine that I've never touched. If I decide to accept a Mac I can check out all of the options at the store over on Regent St any time until the late-ish evening.
Lenovo are just not geared up to retail customers - that might not be an issue at the moment, but I can't help but think that today's retail customers are tomorrows corporate buyers.