The Arlanda Express train is quite expensive (640 SEK RT for a single rider), but it's more…read moreconvenient in terms of time table compared to the other train options which come less often. Also if you're flying from Terminal 5, you save some time from walking to the transit hub at Terminal 4. Essentially as soon as you exit Terminal 5 baggage claim, you walk directly to where it says Arlanda Express, and take the lift up and you're on your way to Central Station.
If you're traveling with multiple people, make sure you buy your tickets together because they offer a multi passenger discount. I flew by myself so I didn't get to utilize this discount... next time!
There's no assigned seating (it's open seating!), so just hop on and find a seat (and a place for your bags). It saves time from having to find a specific train car or assigned seat.
At Central Station, Arlanda Express operates from Spår 1 & 2. There's quite a bit of gravel outside the station, so I recommend walking inside the station vs dragging it through the gravel outside. Time and distance is the same.
I flew SAS, so when I returned to Arlanda, I took the escalators up to the side that said Departures. Follow the signs up, and you'll reach the check-in counter directly in front of the escalators for SAS. Fast Track are to the right of the escalator, for those who don't have any bags. Pretty convenient if I might say! All in all, it took me about 40-45 minutes to complete my journey from Central Station to the SAS check-in counters & Fast Track.
So while I paid an arm and a leg for Arlanda Express, it was very convenient since I didn't have to walk too much to get to/from Stockholm. It was nice that at T5, it literally drops you off right at the SAS check in area.
Given the high price point, I give it a solid 3.5 stars rounded down to 3 stars. If the price can be cheaper, I'd definitely give it a higher rating.