We choose Disneyland Express because we thought our kids would enjoy riding in such a cool looking Disney bus.
I didn't make reservations for Disneyland Express from LAX, but we went to the bus stop, bus arrived within 10 min, took us to DLH, we all stayed on the bus, someone collected the fare, I paid r/t, and made reservations for when I needed to be picked up, they gave me tickets for pick up, they then dropped us all off at our hotels, we were the last people to be dropped off, we stayed on Harbor Blvd (Park Vue Inn).
Having done that I would recommend the Super Shuttle (which we've done on previous trips), DE dropped us off at their curbside bus stop (same one as a public transporation/bus) and we had to walk with luggage + our children to our hotel (which was NOT what I was expecting), we also saw others walking to their hotels quite a distance. We waited FOREVER for the right bus to come get us, it was HOT that day. I think that if you stayed at The Anaheim Fairfield Inn it wouldn't be that bad, since they have their own bus stop at the hotel. But it wasn't worth it IMO. Esspecially if you have kids.
Hope this helped.
Aloha....