I heard both of these speakers at the New York Audio Show last month.
Andy Singer of Sound by Singer was exhibiting a Raidho floorstander, I believe the C3.1, powered by top of the line VAC preamp and amp. I thought the treble sounded somewhat harsh/edgy and the mid-range had a veiled, "plasticky" quality. I did not like the sound of the room either day I was there. And I usually love how VAC sounds, so the problem was either the room or the speakers. (I actually thought the Raidho monitors driven by Merrill Veritas monoblocks in another room sounded better than the floorstanders.)
Philip O'Hanlon was exhibiting Vivid Giyas (I think the G2, but might have been the G3). I thought they sounded good, better than the Raidho floorstanders. However, they were too large for the room, so the bass was a bit overwhelming. But if you like deep, visceral bass, you should like these speakers.
Honestly, I was not completely wowed by either speaker. I preferred the Coincident Pure Reference Extreme, among a few others. But if I were choosing between Raidho and Vivid, I would get the Vivids.