Keith Law has scouting reports for the Rangers and Rays on ESPN's Insider and says that Texas is not as good as either AL East playoff team.
The Rangers' playoff hopes hinge as much on the health of Hamilton as anything else, as without him it's a very ordinary lineup, and their run prevention, while good, will have to reach another level to support such a weakened offense. They do have one other potential savior in Lee, who's an excellent candidate (because he's efficient and because he's likely leaving as a free agent) for work on short rest in October, and their relief corps is solid.
Led by Joe Maddon, a shrewd tactical manager who has proven himself adept at managing a bullpen and mixing and matching position players to maximize value from positions at which he has no clear regular, the Rays are a very dangerous postseason team. Their run prevention rivals that of any other playoff club; they have the shutdown relievers to hold a late lead in the final innings; and their offense is at least good enough to work some deep counts and try to get the opposing starter out early. There's no clear favorite in the AL as there is in the NL, but I do like the Rays' chances to get to their second World Series.