I guess one benefit of the amp plus cab route is that if either component fails you can use backups whilst it's out for repair, if you have them of course.
I went through the CMD121H plus traveller 121H cab to my LM3 with two traveller 121H which was better, to a CMD121P with traveller 121H but ended up with my LM3 and two NY121P cabs. The LM3 and two NY121P cabs is not massively bigger than the CMD121H combo but is significantly more capable.