Vision vs Brilliance for a Westbound TA?

I'm helping someone look into a possible TA in 2019. Vision leaves out of Barcelona in late Sept and Brilliance in early November. Brilliance is 2 more nights and one added stop but from a quick look, seems to be costing quite a bit more. Any thoughts on major differences between the two ships? Not a family so no need for bells and whistles--mainly entertainment and places to sit and enjoy--may be a solo passenger.

The time of year of the crossing doesn't matter unless there is a thought that one date might be much better for the conditions of the crossing.

Thank you!

Also a Solo traveler. With me I choose the better Cabin and price. Love my Radiance Class, have 200+ nites so far another 100nites in 2018/2019 all in Corner/Aft cabins. Though next Spring taking Vision TA because cheaper, extra days, price & cabin a Corner/Aft...

The ships are similar, but we like Vison better. Larger Centrum and bigger main pool deck than Brilliance. However, you do lose the outside Windjammer seating and cinema room on Brilliance.

look at the stops if you have the Canary islands it will tend to be more Southerly and usually warmer vs the Azores.