Same as Rudi...never heard of United comping 1K to anyone. So, just picked up the phone and called the MP Service Center saying I knew a AA 200K flyer and was told Premier Executive is the highest they will comp for one year (upon proof of similar or better status at a competing airline). Asked to talk to a Supervisor just to make sure and she confirmed this. She said that 1K is the only level that absoulutly has to be earned. She very nicely tried to sell me on the fact that PEs get the same 100% bonus miles as 1Ks, but when I mentioned the other perks that they would be missing out on, she said she was sorry but PE is the highest they will do, period.
LAX 1K, maybe you got a rookie agent who misunderstood or gave you some bum info. I'd call back and be specific on your request rather than just accepting that they will "match."