Hi Carrie
Must admit I haven't been with Portland/Thomson for years, but have been with Eclipse 3 times recently. It will be interesting to see how they compare. I've heard that FC planes are now alot newer than the Thomson fleet.
I did get a good price with Portland for the CP, 300pounds each for a weeks B&B. I took 2 rooms as it was cheaper than a family room for 4.

I checked the prices every couple of days as they seemed to vary and then when I felt I couldn't leave it any longer I booked.
There is a whole thread on the CP but I think its fallen off onto the next page.
Provided my kids take to the snorkelling they won't be bored. I'll post the review on my return. Hope you manage to book something.