Okay, I heard this said on their forum and maybe to a degree it's true - the first million skill points (after you leave battle academy) is the hardest. After that you've probably invested in both the armour skills (unlocking the slightly better basic armour plates and basic repair) and shield skills, as well as maybe putting assault rifles to three or so and using the GEK rifle.
You'll still run into tough stuff, but it's probably mostly a co-ordination thing - the other side actually uses mikes and keeps together as a group, heals the heavies, etc. When your own side likes to run in various random directions at once, you are usually fodder for a co-ordinated group.
It's also worth going into the explosive tree if you want to try out anti shield grenades or AV grenades - which are really just anti vehicle landmines which apparently float toward vehicles (but are useless against people).
Also I enjoyed a bunny hopping enemy today who bunny hopped into the path of his own grenade and died. Mostly dudes stay on the ground in this game, thankfully.