The Typhon Pact Arc I've found to be a really mixed bag. A lot of times it hasn't lived up to what was setup in "A Singular Destiny", and has really felt more like Starfleet vs. the Breen/Tzenkethi. Sure the Romulans, Gorn, Tholians and Kinshaya were part of the original Pact, but they've really been sidelined (the Kinshaya have only appeared in the ebook, while receiving mention in a few others). I really hated how the two Romulan states were reunified for this arc---I would've preferred to have seen the two states continue.
Also, I would recommend avoiding "Seize The Fire" or it's sequel "Fallen Gods". They are both "jump the shark" books for Titan.