Have been scammed for almost 1yr....

Since POF release I was told Soulbeast + pet's prowess give you +30% running speed. Never pay attention if it's true until today. Run with a thief with signet of shadow. Both of us have no swiftness boon, guess what? the thief run faster than me ! Soulbeast definitely give some speed boost but clearly not 30% becoz when out of beastmode I run even slower. It may give +15-20% speed boost something.

The 30% run speed has not existed since PoF launch. It was a change they made later. It is also only in effect when merged w/ beastmastery traited.

Not sure what's happening on your end, but whenever I run with a guildmate who's using traveller runes I can definitely tell I'm the faster of the two of us.

It gives 30% movement speed IN BMode, not out. If OUT, your pet gets the 30% movement speed.

As for VS a Thief with Signet of Shadow, I don't know.

Uh last I checked speed always use the highest value. If a thief has 33% from swiftness and a ranger has 30% from a trait and 33% from swiftness... You are both running at 33%. But the thief will probably beat you out in teleports (not to mention 50% speed while stealthed if traited, or whatever it is). Could also be using speed runes.

SoS is 25% and has been for years. In-combat swiftness outruns it fairly handily.The 30% in BM works as it only starts falling off to swiftness after very extended durations.

Either you were in combat, didn't actually have BM traited + merged, or he had swiftness with Speed Runes or some source of increased movement speed.