i've had my kobo mini for several months now. before that i used to have a sony prs-350. after using the kobo mini for a few weeks i sold the sony. i liked the sony but the kobo, whilst having the same size screen as the sony was a little bit smaller and easier to transport and hold. i also prefer the software on the kobo in comparison to the sony offering, and it's also much easier to side load books onto the kobo. i had nothing but problems with the sony desktop software and trying to sync my books across.
if the mini had a built in light like the glo it'd be a perfect machine.