Recently I had a little bit more deep experience with Energia and the MSP430G2553.
Here some notes about this experience.
I did two projects so far using Energia and I have to say that a) I was able to do them really fast (well, the first one with a big start with the help of Roberto) and b) they are working surprisingly good.
For fast prototyping I would say that the MSP430 plus Energia is a good platform.
What is not good ?
Well, is really missing a decent debugger.
I had some strange problems, like for example a restarting code without any clue about "why", or strange behavior events using the I2C on a MSP430G2452 (I solved that using the MSP430G2553).
Very very hard to figure it out these problems without any debug tool.
But also to test the logic of a sketch even a basic debugger would be a great thing.
The second big Cons of Energia is the needed memory.
It is mandatory to use chipset with at least 16K for very simple projects.
The second one I'm working on (I'll publish a separate article on that) already is over 12K and is far to be completed.
I'm sure I'll reach a point where I'll have to migrate on a bigger board, like the F2259.