Arguments for and against both choices to be honest. Manilla is 1 of the rather quicker processing VO's but VO's handling outland applications have become slower. Mine for instance increased by 2 months in the space of just 5 months. So your never certain processing times will stay as stated.
I guess the answer boils down to a few things, do you have children who at some point might want to see their grandparents (I assume they are in manilla) or are you certain you will remain in Canada for the duration? (note the duration of an inland will almost certainly be at least 6 months longer than an outland)
If you want to be able to work ASAP then I say hesitantly that inland might be quicker when you factor in you have no moving and tying up loose ends in Manilla before you come to Canada. Inland you will be able to work at around the 6 month mark, whereas with outland and factoring in time scale to tie up loose ends you will probably be looking at approximately 8 months but you will be a full PR at that point whereas Inland you will have to wait for the complete duration which is likely to be 11-14 months.
Somebody said Inland has a lower rate of refusal than Outland, this however does depend on your VO, My VO has a very very high approval rate (I believe 95%) not sure about Manilla, you would have to check the open data. Not sure what the inland success rate, I believe I heard a 97% success rate. So for me personally there really wasn't much to gain from going down the inland route although the waiting without my wife during the process really did test me to the limit and sometimes I did wish I had applied inland. Now my road is virtually finished, looking back in hindsight, I think outland was the better option because once my COPR lands at my door that is me finished with CIC.
In summary it is really hard to advise, if your VO was 1 with a wait time of 11+ months then I would say 100% inland is the better choice providing you accept you can't leave Canada even for holidays (something I would have had a hard time with). If your VO is less than 11 months then it really is a difficult choice and given inland has been speeding up a bit of a guess.
Alternatively you can file an outland application whilst inland and that is also a very good option.
I wish you good luck
