the s-line does have hard suspension. As it is lowered 10mm over the sport version. The sport as you found is a comfortable, soft suspension and any pot holes hit, absorb this. Especially with road humps.
As for the S-line, the driving feels better over the sport because it just feels more sportier. Including it's road handling. The profile on the tyres are different also in this aspect, because the sport is 17" alloy and the sline is 18". In reference to your question about the suspension, yes every road hump, pot hole can be felt. It's not as extreme as say a customised car modifiers suspension, your mates may have on say a corsa or clio (or similar hatchback types)
As onemanparty recommended i truly advise you go out and drive an S-line. I think if you liked the Leons suspension then the s-line won't disappoint. I have owned both the sport and s-line versions and i'd choose the s-line any day! In addition to the suspension you get the extra trim detail. Chrome exhaust, sporty rear defuser and sline spoiler, matt finished interior and s-line aluminium door placards. Part leather/cloth seating with leather handbrake and gear knob. S-line style steering wheel. Bout all i can think off the top of my head.
As for pictures of my car; :biglaugh:
https://www.vwaudiforum.co.uk/forum/s...742#post460742