I tried it out on the San Joaquin a couple weeks ago going from Bakersfield to Sacramento. It worked pretty much everywhere. Some locations are faster than others. I compared it to a Verizon 4G MiFi I had with me and the MiFi connection is much faster. But the Amtrak service is convenient and free. The train was lightly patronized that morning (Friday 12/2). I would imagine with a crowded train sharing the access point it might slow to a crawl. Overall though a welcomed addition that helped make the trip more enjoyable and productive.