Who said mr/mrl better to have? with attacking middlefielders opponent can not apply offside trap on you. Your wingers with red arrows will turn into strikers- with blue arrows middlefielders.
Its one of the most flexible formations there are because with a few arrows you may have over 10 formation variations.
Its true it can be countered, like every other formation. Personally I get in trouble when opponents play ultra defensive like 5-4-1 or 4-5-1 flat. Butterfly formation can also counter it but for me hardest is when ultra defence is used.