Not much to dislike here. The Flames desperately need help on defense and Smid fits the bill as a top 4 defensive d-man. While I suspect the eventual hope is for one or more of Sieloff, Wotherspoon, or Ramage to step into the role of defensive d-man capable of playing top 4 minutes, all of them are probably a year or two away. Smid should provide some stability in the meantime.
The Flames have a glut of forwards with 3rd (or optimistically 2nd) line potential. Horak is one of the older players who fit this mold and seems to have fallen behind the likes of Reinhart, Knight, and Hanowski on the depth chart. Perhaps he'll find his game in Edmonton, perhaps he'll continue to be one of those guys who doesn't score enough to make the top six and isn't tough enough to make the bottom six on an NHL team. In any case, a top 4 d-man > 3rd line forward.
Broissoit for Roy is a wash IMO. Both guys had good junior careers, but neither seems to be lock for an NHL job. Until they prove otherwise at the NHL level, goalies are a crap shoot.
Not sure how this makes sense from Edmonton's point of view. Their defense was thin with Smid and now it's even worse. Big gamble on Horak and/or Broissoit for them. Or perhaps they're pursuing the "Play bad for Ekblad" strategy