Nick from BrewBit here, just wanted to mention that we are fully open source also. If we go belly up, you will always have access to the source.
http://github.com/brewbit/model-t
Don't want to use our web service? By all means, create your own personal one. That is the beauty of open source.
We also have tons of free I/O on the board and 100% approve of hacking it to fit your system. We even did a video demonstrating interfacing with an arduino to read a humidity sensor. Our goal with BrewBit was both flexibility for those that want it, and also ease of use for those that just want something that works out of the box.
On the subject of cost, I think we are actually a bit cheaper when you include the cost of a Raspberry Pi and other things that you need to get it up and running. We did a blog post on the topic, and found that BrewPi ends up costing $245 or so when you include all the extras. Please do let us know if we are missing something though.
http://brewbit.com/blog/55716064034/brewbit-model-t-brewpi-comparison
All that said, I am not trashing BrewPi in any way. It is also a very good and flexible product, and it absolutely does do some things that we do not. As you said, there is no right answer, only what works for you. Just wanted to make sure all the facts are out there for a fair comparison.