Ok heres my official findings after 4 days of testing and just sharing some info
APN settings does affect battery life and its quite substantial.
2 days on "internet" and 2 days on "e-ideas"
charge up to 100% before i go to bed and leave it on standby till morning abt 9hrs of standby
"internet" - drains about 10 to 11 %
"e-ideas" - drains only 2 to 3 %
daily usage harder to monitor but under "e-ideas" setting my batt can last about 2 days while "internet" setting 1 working day come home left with 20 to 30%
but have to add changing to internet does give a super duper speed boost
Note : this applies to my phone only......