first of all make points for both the schools - current and new ones
both negative and positive points

then ask yourself few questions like

1. why do u think changing to new school

if they r teaching something extra or using different or innovative way of teaching? - then think about "can u include that way of teaching as a part of home studies as well instead of changing the school"

2. i mean just check what extra/ attractive they r giving than this current school, weigh how much extra (or worth) it actually is

3. are u not happy with current school (question of he being unhappy is ruled out by u only in ur post) if u r not happy then jot down the points why u r not happy, can it be solved by talking to teachers/ management?

check all the points, but don't change the school just b'cas they r advertising something eye catchy.

i m not telling u to stick to old school but just weigh ur options by taking into consideration plus and minus points of both the schools

i agree with jyotsna,
change only if required, it can be very drastic for the kid.