Whatever you do, expend the effort to fully determine if switching will be of real benefit, ie. something you LACK the ability to do. Plan the transition carefully, make all changes behind the scenes, then, when ready, make active. In any case, massive overhauls/changes in sites have resulted in loss of traffic and search engine rankings, until the SEs and users trust/validate the change. Keep that in mind.
Welcome to WebmasterWorld! It can be cumbersome to apply your design to the new CMS as you'll need to learn where everything is - and then there's the issue of porting content, 301s, and rebuilding the index authority and link juice you might loose from the switch. Impossible? No. Time consuming? Quite possibly.