Just thought I'd blunder in with my two cents (please, no backlash)
I borrowed a mates new pair of Sidi Vertigos when I first did my CBT, and they were really comfy, great feel etc. After that I decided on the Sidi B2 Goretex which the same mate picked up for me for £190 from the BMF show in Peterborough.
They are as comfy as the summer boots, you can feel through the sole and they're warm and 100% waterproof. The only thing I'll say is that the they're the same size as the summer boots I borrowed, but feel like they're 1 size too big, so I've just put some orthopedic insoles in, which fill the gap, and still provide the feel. My fault for not actually going along to try them out.
They've lasted me 4 years of year round riding, and they're the only boots I have for both summer and winter. And I've been told that they can be resoled.
The wife's got a pair of RST Paragon waterproof boots and she thinks they're great. Not tried on a pair myself so can't really comment. No toe sliders though.
Simon