I was in Anaheim for a couple of days (going to Disneyland) and decided to go down to San Diego to meet a friend for a Weezer concert. I didn't really want to fight that horrible traffic on a weekend, so she suggested I try the Amtrak train. I did some research and decided to do it, leaving from the ARTIC station.
You can get FREE PARKING at this station for up to 14 days. You must register your car online at least 24 hours before your trip. The lot to park is in the back of the station (Lot B), which confused me a lot. The signs aren't very clear, so just note that you must park in the rear. The lot isn't well-secured, so I wouldn't want to leave my car for more than a couple of days, max. I left my car overnight with no problems.
The signage at the station isn't great. I started to panic because I couldn't find a sign board that said what platform I could find my train. I finally figured it out, but it wasn't easy. Make sure you arrive early.
There's a help desk on the first floor if you need it, and restrooms throughout the station. Ample seating, but not a huge amount. You'll find a selection of vending machines which are nice if you want a snack, and a library kiosk if you want to borrow a book for your train ride.
Be aware that a lot of the local homeless population like to hang out in the station, especially the bathrooms. I was there at 9:30 am on a Saturday morning and there were two women taking a bath in the sink. Another guy with mental issues was ranting out front. I wasn't super uncomfortable, but I did eventually go outside and just stand on the train platform with other riders for an hour before my train.
This is a really nice facility, and I'm sure I'll be back to ride the train again. Much easier than driving to San Diego from Anaheim!