The biggest pro of the Beco is also its biggest con in a way -- the safety harness that buckles your baby inside the carrier. For many people who are otherwise too uncomfortable with the idea of getting baby on their back by themselves, the safety harness is a godsend and enables them to do back carries by themselves without assistance. It also enables one person to pass baby and carrier off to another person without taking baby out.
But the safety harness always has to be used, and requires an additional step -- baby has to be buckled into the carrier each and every time. This is not bad at all in the younger months when baby pretty much stays put -- but getting into the toddler years when baby wants up-down-up-down all the time, it can get cumbersome.
So really, it's one of those "you pays your money and you takes your choice" situations. If you think you really need and/or want the safety harness and you're aware that the tradeoff is a bit more effort to get baby in and out, then go for it. If you want something a bit simpler but with more of a learning curve for back carries, then you might consider a different buckle carrier. There are lots of good brands out there, any one of which would last you from now until you're done babywearing.