I've got a Bravo one and while it is durable, it is easily outclassed by other markers.
It all depends if you are playing for a bit of fun or do you intend to take things a bit more seriously. If all the people you are playing against are similarly equipped (ie mechanical triggers, gravity hoppers etc), then a Bravo One is fine. If you are going be playing against people with electros and higher end milsim, then you could stuggle.
Whether you should get a milsim marker is all a matter of personal choice, but if you do like that look then be prepared to spend some cash - the old adage "you get what you pay for" does apply and milsim markers & add-ons can get expensive.
I decided to go with mil sim to start with and bought an Bravo One and then an X7 but after a while found I prefered using non-milsim style markers. If you can, see if you can try out some markers at a walk on day at your local site and find out what you like before you buy - it may save you money in the long run (I wish I had done that as I now thinking of selling my Bravo One & X7 to fund my growing Autococker habit...).