Is that dislike granted? or am I just biased?
You're just biased.
Please don't take this in an offensive way, but I think maybe you're being blinded by your Windsor experience. The Sebo and Windsor cleaners are pretty much exactly the same - they're certainly exactly the same in day to day use and performance.
The Felix is essentially like using a canister with a powerhead, but in the upright position - high suction power combined with a motor driven brushroll that really gets deep into the carpet pile. Despite my preference of the X range, I honestly think the Felix has greater suction power through the hose. It's ideal for homes with lots of nooks and crannies, small homes or homes with lots of different flooring. And, of course, it's very solidly built. My Mum has one and she absolutely loves it.
Why not try going to your local vac shop or showroom and trying a few out before making a decision on which is best for your home?