I like the signings so far. They all seem to have have a winning attitude and/or playoff experience. Also on the positive side, Buffalo has kept most of both lines along with Taylor/Watkins/McCoy. Keeping the core of the team and adding players that fit the new culture will be a good thing in the long run.
Short term, there is still a ways to go. As of today, there are 43 people that are on the Bills roster and not restricted or unrestricted free agents. Among that 43 include a few futures contract players that will likely not make the roster. There are only 6 draft picks. This means that there are many holes to fill and there are going to be a lot of new faces on the Bills over the next 3 months.
I am hoping that this isn't a rebuilding year, but there is still some uncertainty as of today.