I have used both maxsea's and expedition's routing quite a bit, and I will say again that generally on a cruising boat I find it a fun toy but not greatly valuable. The plain fact is that we (cruisers) don't generally go fast enough to be able to play with weather systems and have many options.
Its quite different on e - w passages than on n - s ones. On east - west passages you can go a little north or a little south but basically the weather is going to come over you no matter what you do. On north - south passages you have more leverage on the weather systems and can choose to go in front or behind or a pattern crossing below you so the routing analysis is a bit more useful here, but you need to be careful because the multi-day gribs are often not so accurate and you don't want to make a big routing bet and then have the weather do something completely different. Most of the world cruising routes are of the east to west variety with only a few common north to south ones (fiji to NZ comes to mind)
I can only remember two passages where I did something slightly different because of computer routing than I would have done just looking at the gribs with my eyes. On a passage
from NZ to Polynesia I tucked in behind a low pressure than was coming down from over the top of the North Island a bit later than I would have done on my own and it minimized the time we had headwinds (but did give us stronger ones for that time), and in a passage
south from Iceland
to the Canaries
I again tucked in behind a low, this time turning winder than I would have on my own. But mostly 95% its pretty obvious what a cruising boat should be doing - just plodding along toward the destination
In any case . . . someting fun to play with . . . but better to first take your time to understand the level of certaintly (sometimes high but often quite low) of the forecast
and the possible alternate senarios that might occur and then you can know if you want to place a tricky routing bet or not.