I went there twice, both flying + renting a car,

at end of Aug to early Sep. Weather was descent the first time, great the second time.

The advantage of DIY is you have all the freedom, you can do whatever you want, for as long as you want. The disadvantage is you have to plan everything yourself, and find a descent place to stay at the end of the day (to stay flexible, we hardly booked anything in advance).

The good thing about Cruise is they plan everything for you, so you can relax. The bad part is no freedom.

I think cruise is good for family (with small kids especially) and senior. If you are more adventurous, DIY is better.