depends on the difficulity really

if its on easy dont bother with cheats if ya good at half life and wana see the story but if ya wana put it on hard then dying might get annoying if ya trying to see all the story lines and dont want to get stuck on certain bits cos u have low health or no ammo

hehehe thats my justification of cheating anyway but i still try not too as must as poss... been playing the origional quake on nightmare... name says it all in later levels