I tried to contact the organizers a year or more ago about the course, when I wanted to start getting serious about
permaculture. I was discouraged to receive no reply to any of a number of emails that I sent. I eventually decided to just do as much research as I could on my own.
There's also a meetup group in Belfast but that one isn't really doing anything yet. They've got a few dozen members but there's almost no discussion.
I feel like between all the free resources online and the
books available you
should be able to get a good understanding of
permaculture design. Beyond that, it's really all about tinkering with things and networking. A good
PDC should provide a lot of that practical real world
experience to help visualize the process. I'm going to see how
Geoff Lawton's online course goes this year for those who are taking it. If he offers another one over the winter I'll probably invest in that. At least that way I have a legit certification from Geoff and PRI. At this point a PDC for me is about fine details and networking and less about the basics of
permaculture.
That being said, I've not heard anything good or bad about the Portland Meetup PDC. I also do not know if the PDC they are offering is "approved" by Geoff or PRI. For some, that's a sticking point.
Hope that helps some.