From my experience:
Standard blade: medium lift blade, low wings on the ends of the blade
Mulching blade: low lift blade with longer cutting edge at differing heights along the blade. You can use a deck plate to cover the discharge chute to not allow the grass to leave the deck, and it continues to get cut up into smaller pieces.
High Lift blade: taller wings on the ends of the blade. Helps if grass is wet or has high moisture content. Discharges grass a good distance and spreads well
Flat Blade: as you would expect, no wings on the end, low lift.
Gator Blade: a high lift blade with a high wing on the end. Wing is segmented so it has multiple cutting edges to cut the grass multiple times before it is blown out of the deck. You can use a deck plate to cover the discharge chute to not allow the grass to leave the deck, and it continues to get cut up into smaller pieces.
I use high lift blades on my mower during spring and early summer when grass has more moisture. Gator blades and mulching blades can clog up the deck my cutting the grass until it becomes soupy under the deck. Then I switch to gator blades during late summer and fall. They do an awesome job on leaves - I live in New England so we get a lot of leaves. A few passes of the gator blades with a chute plate and there is nothing left of the leaves. Instant mulch!
If your field is dry and dusty, you don't want high lift blades. You would want flat or low lift blades to keep the dust down.
