Hello, I'm not an expert, but I think that the reaction wheels power are very (too) powerfull...
This is a lil bit of cheating isn't it?
For example, take the Mk1-2 Command Pod, jettison it on space, and apply full pitch or/and roll... The pod will just rotate close to the light speed and the Kerbals inside will just have a brain attack.
This issue have to effect to make useless the RCS for the little ships...
Thanks and regards.
EDIT: to complete my statement:
The RCS is just totally useless in attitude adjustement for a regular sized ship...
I think this is a lack in the gameplay, because the reaction wheels are very light (more light than a RCS tank :)).
It is more intressting to add a SAS module than an RCS with monoproplent tanks...
Please, read the statements in this thread before voting...