i've used super all but about ten times in my impreza wrx- tbh i've noticed very little difference in it power/ fuel economy, and the filler cap says 98+.
Yes, but what type of 'super'? Becauase they aint all the same. Most supers in the UK are actually only 97 RON - so hardly an increase over the standard 95. But Shell V-Power and Tesco 99 are both 99 RON - which is really quite a difference over 95 RON.
Secondly, because you 'normally' use 95, then your ECU has probably 'adapted' to run with less advance on the timing as its 'default' settings - and when you do occasionally give it a splash of super, the ECU doesn't have long enough to properly adapt, before you end up slinging poverty-spec juice at it again!

in fact running a tank of 95 after 98/99 seems to be better if anything- but the scoob doesn't have a range computer- just a rather uneven fuel gauge.
That IS a well known phenomenom in that scenario, across most makes of car. The in-depth answer is a bit 'tecchy'.
i'll probably give the gti a test and if i see a benefit out of super i'll use it, otherwise i'm planning to go back to regular
If yours is a Mk6, then it would seem you may not actually notice any benefit with super.

With a remap though, that is different!
