The strange thing is not too many people seem to be using Taglocity. At least not the people in my network. Lots of them use Xobni, as I did too. I tweated my network, searched Twitter, Googled a bit and found their isn't a whole lot of buzz on Taglocity yet. Well I guess I'll have to create some and lead the way... ;-)
Ok, now about Taglocity. As I said I really enjoy Gmail functionality. Taglocity brings this to Outlook. And it works for me. I really enjoy adding labels to my email. I still put mail in one of the 6 folders I have (of which the biggest one is 'Deleted items'). But I now also label them. This makes finding my email back much faster. And I don't have to be to anxious to put the email in the right folder.
The search speed of Taglocity is good enough. In practice I switch between Outlook search, Taglocity search and MS Desktop Search. Just depends on what nearest. What I really like about Taglocity search is the fact that it searches all my Outlook folders and archives. When you move emails to your archive it reindexes pretty quickly. The start-up time of the Taglocity search client could be quicker though. Furthermore, when I query I would expect it to search in my tags first, but default is full-text search. Filtering your search results using the labels works wonderfully. (As in most search tools, give Taglocity some time to index your mails when you start using the plugin!)
Adding tags to your emails is very easy. No explanation needed here. You can even add a tag to the email you are going to send (- this is not that easy in Gmail). It would be nice to have colored tags as Gmail has. You can also add tags to people, but I don't use it. In the search client, the tags are not in alphabetical order, for some reason.
I don't use the 'conversation viewer' often but it works and is great. (Of course you can turn on the conversation view in Outlook too, but Taglocity's feature let's you switch between the views with one mouse click. It's not or-or, but and-and.)
Relating to Xobni, Taglocity also has social network features. You get some stats saying how many emails you sent, received and cc-ed to the person. This is nice, but I don't really use it. It would be nice to have the Xobni 'schedule meeting' functionality in Taglocity.
Does Taglocity slow down Outlook? This is a very important question to me. If the plugin would slow things down, I'd quit using it right away. Up until now I don't think Taglocity slows down my computer and/or Outlook - other stuff is doing that...
Oh, and if you wondered: I'm not going back to Xobni.