Cops are not hard to escape from. As for them ignoring the Lester call, it seems to be random, although I've found they ignore it more often when I've killed cops. They definitely seem more aggressive after the last update, one star should not have police shooting to kill. What is really infuriating about them is the way they get involved with "freemode player vs. player" battles. they need to leave that alone. They don't show up when I kill gangbangers that shoot at me, but as soon I kill another player (that attacked me first) they're swarming everywhere taking the fun out of pvp.
I'm all for "No Cop" Lobbies!