Are you using the latest (2.2.8) version of Freerange? Posting to del.icio.us takes 2 clicks (well, technically 4 if you count menu key strokes); click 1 from the menu takes you to where you add tags, click 2 posts it. If you have "show confirmation" turned on, then there's a 3rd click to dismiss that (but I turn it off).

I'm not trying to make this sound anti-Viigo, but facts are facts. I just did the same thing with Viigo and it's Delicious support is amateur compared to Freerange; you cannot set 'not shared' in Viigo, you can't post it to Delicious from the article list (you have to be in the article itself), there's no global config to store common options. Viigo also does not allow you to enter notes when posting the article, but Freerange does. In short, Freerange support all the Del.icio.us features whereas Viigo supports just the basic idea. (but it's great they both support it!)

I also don't feel slowness - Freerange 2.2.8 and Viigo 2.2.70 feel the same speed. This is on an 8320 though, I don't know how it compares to the 8300 you list, maybe there's a difference on your device or OS (it happens). Viigo is definitely really zippy though!

What I do like a lot about Viigo is adding/searching for new feeds, they've got a superb interface for this and it's much richer than what's offered by Freerange. I also like the special Viigo Bulletins channel they have, and the status messages are really cute (i.e. during setup it's "Please wait while we connect some wires..." and such, a little humour). It's nice when a piece of software has the human touches like that, it gives you the warm fuzzies.