depends how well u ride kapcai, and how fast u think u are at learning clutch bikes

now, if u ride kapcai, is it disbrake or drum brake? aggressive riding or slow slow almost never need to brek? do u brek with all fingers (except the thumb) that hold the handle, or u already very good can do 1 finger or 2 finger braking

when u use clutch later, r u going to do the same? all fingers clutch the lever? or, u will ride with 2 finger clutch?

when u ride bumpy roads, do you panic and tense body? or relax and let the bike handle the roads?

above question means if u are able to handle kapcai confidently, i think u can learn big clutch bikes easily

R15 is still R15, is kapcai engine put on sportbike fashion
R25, Ninja 250 and CBR250RR are aimed at higher performance, their speed can lawan some big CC machine like CB500, Kawa650 etc, but of course the power (torque) is much milder than big cc, as they say 'no replaecment for displacement'

weight is another matter, and only can manage from practise slow speed control, JPJ mandate titi, tight roads, U turn and figure 8 are the good examples that can save u during traffic emergency, so when take heavier bikes these need to keep practise

if travel with friends, do take care of each other, and make sure no new riders get left behind, i ride fast fast but got new members I sweep their backside from a distance away, make sure no give them stress and learn to enjoy the first maiden ride

anyhow, buy the bike u really like
if end up the bike no suit you, if can adjust, learn to adjust
is better than buy the bike u no like, end up rosak here rosak there u also lazy to fix it and disappointed with the whole biking experience

good luck to you and hope to see u on the road some day