I came to the Superb from 10yrs of two Volvo XC60's, fancying a change after nearly 20yrs of SUV driving and haven't regretted it. The car is aptly named and you get an awful lot for the money. It certainly didn't seem like a step down from my 5yr old Volvo, techwise it it was quite a step up but it is noisier and Volvo are renowned for the comfort of their seats and though the Skoda are certainly not uncomfortable, they're not really in the same league.
My only real gripe is with the DSG box (7 speed on the 1.5 petrol), it's mostly very good when you're moving but there is something of a lag when you're pulling out at junctions or roundabouts, you can almost count to 2 before anything happens when you press the go pedal! Same with kickdown for an overtake.
Recently, having having reached the grand old age of 3 score years and 10, and adjusted from SUV to Estate I decided to push the boat out and look at an “upgrade” to an Audi A6 or BMW 5 series, both PHEV. Tested both and to me the bimmer edged it by a fair bit. The A6 was a very classy, quiet and pokey, though less roomy Superb, being VAG the layout was similar if very much more refined. The 5 series was a better driving car, IMHO, and was ever so slightly more upmarket than the A6 let alone the Superb.
As others have said, new you're comparing Aldi to Waitrose, Primark to Next. If 2nd hand there isn't the same price differential I'd be very surprised if you didn't find the BMW better to drive, quieter, classier in the interior and less roomy than the Superb. That's not a criticism of the Skoda, just a reflection of what you would expect given the price differential when new.