the path i took was kapchai for 20 years then to a used z250. the transition for me was super easy and seamless and became 2nd nature in a matter of days. so i didnt worry much about clutch and weight and all that. the power increase wasnt that big of a jump to surprise me either. even going thru traffic daily wasnt that bad. though kapchai still easier la for traffic. even took the bike on multiple 6-700km day rides with no issues.

as long as u buy used then itll be a good investment. u can even get them cheaper than a new R15. best part is you can sell it later on at probably the same price u bought it or maybe just a tad bit lower so u dont lose much money. just make sure the bike u buy has all its necessary maintenance done on schedule including the valve clearance.

however, the maintenance will definitely be costlier than an R15 being 2 cylinders and chain and tires will cost a lil more but can still save money if u know where to look.

R15 may be good if this is the first bike ur buying... but ur upgrading, so better to go to a z250.