If I understood right you flew the 500 with V bar and now the 800 has xbar. There is no difference in how those two fd work,regarding bank limits,pitch ,etc.
It's just a matter of getting use to one of them. Pilots consider one or the other to be more accurate,depending on how they got accustomed to them.We have BAC1-11 pilots that love the Vbar (that was on the bac) and think this is the best FD. We have other pilots,first trained on the 737 with Xbar that consider this one to be the best.
Maybe the Vbar will give you a more intuitive picture of the situation,I guess,maybe it's easier to follow.
I think ,personal opinion,that the crossbar it's more accurate,but you'll have to monitor it closely,try to keep the bars in the box.If you'll let it slip ,it's maybe harder to bring the bars together as would've been with the Vbar. For a begginer,of course.
Once you get used to it you'll find it easy to use.
And don't try to blindely follow the FD.You should check the other indications ,speed,Vs...
Maybe one day the FD will fail,or ,more common,will give you some wrong command,you'll have to be aware of that.
All FD's give bank limitation,it's not something that depends of the type of FD installed. It depends of bank angle selector,of the fmc parameters,etc..
brgds alex