A power lawn mower includes at least one cutting blade driven, directly or indirectly, by an engine. A cutter deck assembly of the mower includes a cutter deck, cutting blade(s) housed therein, and a pulley/belt system powered by a drive shaft of the engine for driving the cutting blade(s). The cutter deck assembly is selectively adjustable upward/downward to adjust the cutting height of the mower and/or to allow an operator to put the cutter deck assembly in a heightened position for storage and/or transport and thereafter lower the cutter deck assembly to a cutting position. In certain example embodiments of this invention, a latch system is provided as part of a deck lift system for permitting the cutter deck assembly to be more easily and/or efficiently raised/lowered.