Can Pfizer finally orchestrate a winning megamerger after so many disappointments?

Pfizer’s ($PFE) decision to buy Allergan ($AGN) wasn’t much of a surprise; the nominally Dublin-based Allergan was among the few buyout targets that could deliver CEO Ian Read‘s desired tax inversion.

Nor is it surprising that Pfizer chose to rack up another megamerger, given its history of huge deals. In fact, the record Pfizer broke with its $160 billion deal for Allergan was its very own, set with the $111 billion takeover ofWarner-Lambert back in 2000.

That of-course-they-did reaction to the Pfizer-Allergan merger agreement was followed by a series of analyst notes totting up the financial effects of the deal–the jobs Pfizer might cut, the costs it might save, the earnings that might accrete in the coming years, the buybacks it could fund with its overseas cash