Can’t comment on the s2 but have a Littlelife adventurer
My boy is 15 months and loves it, has even fallen asleep whilst walking. It has a decent sized pocket which fits his lunch, change bag, change of clothes, suns cream and a thin blanket for sitting on. Has two side pockets which can easily fit 3 -4 bottles of water. Decent for a half day out. If we need to carry more I just give the wife one of my other numerous rucksacks to carry, think it cost me in the region of £60-70 which is cheap given how well made it is. (Maybe I’m become numb to spending stupid money on bike related stuff).
Tbh it is quite heavy when loaded up and I wouldn’t want much more storage space as it would encourage me having to carry even more stuff