dost as far as performance of a engine is concerned point is the better option because the ignition timing can be advanced or retarded, there are technical factors involved when it comes to advancing or retarding a engines timing, some people need to retard the timing to compensate for a bigger piston they installed in the cylinder.. while some advance the timing to achieve better pickup but less top speed. but there are disadvantages in keeping a point system too and the major disadvantage would be maintaining a point, a point's life is limited and it needs to be serviced/cleaned every 2-3 months because of the constant spark load it creates
CDI on the other hand is hard to advance or retard since it has a fixed timing curve, until and unless you modify the timing plate on which the pick up coil is installed you cannot modify the timing curve. this is the only disadvantage of a CDI ignition system. the advantage of having a CDI system is that it barely needs any servicing during its entire engine life.
Point waali bike's aanaa sirf issliyay bund hougayeen kyun k they were old technology and needed frequent servicing.. CDI ko service ki zarurat nahi hotee issliyay ab market main jitni new bikes hain sub CDI system pey hain aur point pey nahi.