It's all in the detail Panda - I suspect the carbon construction is pretty different from manufacturer to manufacturer although for overall strength you could'nt go past a Maui Sails carbon.
Of the ones I've used the quality front ends were- Maui Sails, Severne (which are Aerons), Neil Pyrde (although plastic was prone to cracking & don't know if they've fixed issue though).
Boom grip is nicest on the Aerons / Severnes, with NP a close second. M/S grip is pretty hard and is prone to peel away / lift at seem joint so this probably their only negative.
head profiles between ali's and carbons differ i.e. not as rounded at head which can feel slightly awkward initially.
All that said my brother still has an old Autima carbon boom (about 9years old now) that has had head replaced about 4 times and had a large amount of abuse but still going strong as ever. I used it for about 4 years and he's just started sailing again - I'm 93kgs he's 120kgs