I had no issues picking up my reserved car at ANC earlier this month. The counter agent was even able to get us into our car about two hours earlier than our reservation time (our flights had changed after booking; normally not something I'd be concerned about, but this year it did cause me some angst). I reserved an intermediate and got a Toyota Corolla that was nearly new (~2,000 miles or so) but a very plasticy, base model version. Nevertheless, it got the job done.
My only frustration was that the counter agent gave me the choice of the Corolla or a Nissan Quest; when I told her that I'd take the Quest, she tried to charge me an SUV upgrade rate that was several hundred dollars more than my reserved rate. I told her that I thought she was offering me a free upgrade akin to what you'd experience when reserving an intermediate car at a location with an Emerald Aisle (I've got Executive status) and she said essentially "nope, we're not doing that." So we took the Corolla at the reserved rate. Not a significant complaint, since I got what I reserved at the rate that I expected, but it did leave a slightly bad taste in my mouth.