Level 20 is a sudden and massive wall; I'm not grinding fish for 19 hours to increase my stats enough to get past the random groups of 4. Horrible game design in an otherwise enjoyable game. :/
It would be nice to have the option of toggling ally and fireteam unlocks off/on once you buy them. Grenadiers are just crappy versions of AA's and Marksmen really fall off later on in terms of usefulness, but you're stuck with them whether you like it or not.
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