I'm travelling from Salamanca to Porto on April 23. Cheapest option seems to be Gipsyy bus, but reviews are pretty mixed. There is also Flix (costs twice as much). Anybody have any tips? Also, is it best to reserve in advance? There are 3 of us travelling. BlaBlaCar Bus is also an option, but they get some really sketchy reviews.
According to Google maps there is an Alsa bus from Salamanca to Viseu where you’d switch to either Flixbus 1002 or RedeExpressos 180.
There also seems to be an Alsa bus that goes directly to Porto. The Alsa website shows 4 busses on April 23rd to Porto.
I have taken the bus between Cascais and Porto and it was fine. I actually liked it better than Flixbus - which is also fine. Gypsyy has an airplane sized toilet onboard.