The dispatch table is shorter than the switch, so there is a lot less noise. The invocation is a little clever, but overall I would consider them about equally complex. Maybe you meant unconventional?

The performance is substantially different. The dispatch table is ~75% slower (in chrome). http://jsperf.com/switchvsdispatchtable

One thing I really like about dispatch tables is that it forces the developer to only be able to handle the decision logic. The number of times I've had to cleanup a switch with 20-30 lines under each condition (sometimes including another switch) is too many to count.