It's probably just me, but I've always had awful luck with heavy flamer chimeras. I usually use one on my company command squad's chimera and to date it has never killed anything (only been fired once I think!) and there have been many, many situations where another heavy bolter could have fired. Call it personal preferance to stick with the heavy bolters
I agree hordes might be a problem, but I was hoping the 7 multilasers, 7
HBs and 3 large blasts should hopefully be enough to provide the shots to handle orks etc. Do you reckon I should change to flamers anyway?