Long story made short: Normal web browsing all passes through essentially a filter run by WN/Row44 and has the definite possibility of slowing down the service for any given reason. Running something like a VPN bypasses all that and your web browser traffic (and pretty much any other internet connectivity) goes straight to where your VPN server happens to be and is hopefully much faster than Southwest's Wifi.

In really dumbed down terms (and using the over-used gaden hose/internet analogy), think of the stock setup with Southwest's proxy/cache as multiple short garden hoses connected to each other, multiple junctions, and even sediment filters in between which are restricted. Running a VPN more or less removes said filters and reduces the amount of junctions some.

If my flights next week have Wifi access I'll attempt VPN access and see if the service smooths out. I took pretty much the same flights this same time last year and had Wifi access out from CMH to LAS. It was 'ok' for the most part. Some points it slowed down to literally a snails pace with dead pages.