The Park Tool MT-30 is a great tool for fixie and single-speed riders, because it also includes a 15mm box wrench, without which you can't remove the rear wheel on fixed-gear bikes.
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Pros
Pro Great for fixie and single-speed bikes
The Park has the ideal selection of base tools (2.5, 3, 4, 5, 6 and 8mm hex wrenches, T25 & T30 Torx drivers, a combo cross/straight tip screwdriver) as well 8 & 15mm box wrenches, which are essential for removing the rear wheel on single-speed bikes.
Pro Convenient to carry with you
The Park tool weighs 5.4 ounces, and it has a key ring holder for urban appeal.
Cons
Con Not as comfortable as a stand alone box wrench
A stand alone box wrench gives more leverage for removing the rear wheel, which makes the process easier. However, that doesn't mean the box wrench included in the Park tool is useless- it'll still get the job done, just not as comfortably as a tool dedicated for that purpose