They are both excellent machines, both easy to use and transport! The Cuttlebug, however, takes up half the footprint in storage, vs. the Big Shot.
I did an article, based on my experiences, on these two machines, and you can read it
HERE, if it is of any help in making your decision.
I don't think you can go wrong with either one--it is, as someone already said, it's more a matter of personal preference.
Go for the one you fancy most! ;)