I guess it depends whether you aren't satisfied by your S5 anymore or you'd simply like a larger screened phone. What do you expect from making the switch?
Personally I now own the Edge for about a month and I am overall satisfied with it. I can't really complain about any unusual lags and battery life seems to be what one can expect of a 5.6" screen phone with just a mediocre 3000mAH battery.
What I am not satisfied with is the general lack of updates. I own the unlocked European edition, no 5.1 so far, no Stagefright fix and no announcements when any of those land. But I guess you should be familiar with this as an S5 owner :/
Edit: Forgot to mention I accidently did the Lollipop upgrade and really expected worth. Performance seems to be a tad better and even battery live seems to have improved, at least during standby. What I don't like is the screwed up notifications system. With Kitkat a message notification only appeared on the edge screen, with Lollipop you now get that toast message as well es the info on your edge screen. Haven't found abway yet to disable those toast notifications.