octopus briareus live for about 10-14 months similar to a Bimac. But it matters how old it is when you get it. For example I got my Briareus very young (a head size of about 1/2 an inch) so my octopus has a good 14 months ahead of him. The webbing on the octopus isnt always there. (only at feeding time). these octopus are nocternal but are often trained to be day octopus and it is pritty easy. Simply feed durring the day. I nodice mine usualy comes out at dawn and dusk.
As for briareus being more enjoyable I cant realy say. They both have there good qualities. and I have never had hands on experince with Bimacs.
If you look at the List of Our Octopuses, you'll see that all don't live out their full lifespans. While some of these die early due to human error, others just seems to pass away earlier than others, just like humans. So Tom, if you get 10 months, you'll be doing quite well.
And nini, I don't think you can say that a bimac is better than a briareus or vice versa. They are different but both can be nice to keep. Bimacs were more available, which is why our members have kept so many.