What I like of course is this blogging function. I like the write down some thoughts, so this is nice feature. While I was with my girlfriend in Japan we wrote a quite succesfull blog about Japan and our life their. You can still find it here:
gunda-und-thomas-in-japan.typepad.com
Of course it's no longer up to date 
What else I like? It's the statistics (sorry, but I'm a freak about this). Here I can see who when was watching which of my content. That's fine for me, but I fear that will lead to problems if ipernity grows.
The networking I like. It's really easy to see what's going on, finding new people. It's really fine how they managed all this.
A big plus is the reply function. Here I can now directly reply to comments and look for answers to my own comments. flickr has no comparable functionality.
Anything else is okay, it's a flickr clone, so the basic functionallity to share your pictures excists (sometimes I think they could have cloned to much, like the organizer thing, it really looks like a 1:1 copy, only with reduced functionality), the multimedia options are a nice add, especially the possibilty to upload videos wwould have been nice while I was in Japan. We made a lot of them and couldn't really share them 
What did I miss? The internationallity, mainly this a home french people and german flickr refugees, but I miss it to see pictures from all over the world. I had contacts in North- and Soutamerica, in Asia, Australia and so on. I miss this really here...
And then I miss explore. Sorry, but I'm a little bit addictit to flickr's explore. I had a lot of pictures there and I like the resonance that this produce...
Beside that, resonance here is quit good, but manly produced by visits of old flickr contacts. But maybe that will improve...
I also miss the photo centered layout of flickr. When I move to a flickr homepage of someone I get a fast imoression of his work. That's not so easy here, it's too myspace like. Sorry, I prefere the clear, minimalsitic, white layout of flickr!
And some technically stuff: I'm a 'tag spammer', I hate flickr restriction to 75 tags, so more I hate the 20 tags limit here. It's afful!
Geottaging works not so well, or has someone found a possibilty to tag the pictures directly?
he recent activity page of flickr I really prefer. This one here is too caotic for me and I can not change the time I want to look back, or?
There some errors or even strange behaviours: Exploring tags gives allways less results than searching for pics by tags. For from flickr imported pics I couldn't change tags in the organizer. When I go back to the pic, the tags haven't changed. The messge counter is sometime not right, showing less or too much mails. And the tag cloud on the explore page doesn't fit.
That's not much, so mainly the page works very well.
Think I missed some aspects, but for the moment, that's all :)