I do not trust them to increase the block size, that is why it should be implemented by an alternative client. Unless the Core devs increase the blocksize, I will not trust them to do it.
I don't trust Gavin/Hearn to implement anything, since the basis for scaling in BIP101 is Moore's Law (unproven, unscientific, failing) and nothing more than the baseless assumption that we can address issues of scaling on an exponentially increasing schedule. Literally, the only answer provided to questions of delayed block propagation times is that "technology gets better over time." Never mind the basic premise in large scale systems that conditions in small scale =/= conditions in large scale, and how this basic oversight could force us to fork the limit down after a serious security lapse. One cannot test a regime in a .4MB block environment and simply assume that it is stable in an 8GB block environment.
We are simply supposed to believe that "technology gets better over time, therefore exponentially increasing block size limit presents no threats to bitcoin."
Pfff.....
If you believe a block size limit increase is necessary, it doesn't logically follow that you should accept the first reckless proposal that comes along.
You do not need to trust Gavin and Hearn, they have already released the code and everyone can see for themselves what is in there and what the schedule for the increase will be. The Core team however will not even give us a definitive time line for when they plan to increase the block size, so trusting that Core will increase the block size is just that, trust.
I do believe that a block size increase is necessary, therefore it does logically follow that I should support the first proposition to do so. I am not an unreasonable person, as soon as a third alternative presents itself I will most likely adopt that instead. I just do not want to entrust these or any other developers with the future of Bitcoin. Right now we only have two choices, and even if it is a choice between the lesser of two evils, we do still have to choose.