If these are the same one's that are floating around Sydney, i'm fairly sure they're 2C-B. I took 2 1/2 of these last night, and they sure were weird. We were sold them as 'Tripstacy', so I presumed they were some form of 2Cx from the start.
They took about 2 hours for any effect to take hold on an empty stomach, although I do have a slow metabolism, and then it took another hour after that for them to really take hold. We were smashed with a large amount of speedy effects, reminiscent of Methamphetamine/Dexamphetamine (ie sweating, agitation, energy, a touch of paranoia, and a general feeling of being overly confident) which lasted about 45 minutes before a very nice, mellow, psychedelic experience kicked in. This is the first time that we've tried anything under the name of 'Tripstacy', or any 2Cx compound (if that is what they were), but they were very nice, mellow, and grounded, with very colourful and organic visuals. Not much euphoria, though, but they did have an occasional rush to them. They were definitely quite chatty.
All in all they lasted about 9 hours from the time we first dropped them, although we had some fairly intense residual effects for up to 20 hours from first consumption. The trip was much nicer, and calmer, than LSD, Mushrooms, Mescaline and the like. Visuals were interesting, but fairly 'fake' feeling, as in they were something that we could turn on and off as we pleased. I doubt that they had any MDx in them though, due to the fact that we felt no decent rushes or intense euphoria.