Yes there are many buses. The reason I gave 15B is because of its frequency.
27B is direct to EGMORE front side. Also has good frequency (24 buses are running for 50 mins journey so can expect frequency to be 5 mins) but it takes right to Chetpet after Taylors road and take some more time than 15B running time.
They also drive bus like auto and easily navigate heavy traffic so we can expect to reach on time mostly.
Connectivity...
more... wise I love MTC and I started off with MTC(Pallavan/DATC old names) bus fanning before rail. I used to visit Anna Nagar RTO office in Tirumangalam on my way bask to school where new buses with different livelries would be stationed for registration for DATC(TN-02). Good old memories.