Not that it's perfect, sychronisation can be slow, especially when one machine is catching up, and the Mac client sometimes refuses to exit, but that said it's pretty good. Killer features for me have been
- direct forwarding of emails into evernote - ideal for building up folders related to particular conversations, contracts etc, and have them accessible anywhere
- being able to submit pdf's directly into evernote and being able view them in a client window
- ditto with photographic images
- drag 'n' drop reorganisation - life changes and sometimes you need to reorganise your files to make more sense, especially more when you are accumulating material for a project
- it is multi platform, I've switched between mac and windows without problems
- having a web view is ideal when you're working from a computer or a vm without the client installed
- no internal preview for word documents - you need to have a suitable external application installed
- no way of having an object in two notebooks at once
You can also share notes with non-users by emailing them straight out of the app. Nice to haves would include being able to submit straight into Google or Zoho docs, or being able to post to wordpress or blogger - but these really are nice to haves - ctrl-c/ctrl-v works just fine and given that you're probably going to work on the document before sharing or posting it (and the use case I'm thinking of is creating internal technical or reference documentation such as engineering changes) the lack of a direct post facility is pretty minor.
All the functionality is there in a free account. I ended up paying for a premium account because I (a) found it useful, and strangely enough I'm not averse to paying for useful things and (b) got very close to the maximum usage limits on a couple of occasions.
I've also the nevernote client clone for linux on a couple of occasions, but not really seriously, as I'm no longer a serious desktop linux user. When I have used it, it's been more stable than my initial experiences suggested and seems to have had no problems syncing with evernote, which is a tribute to evernote's robust architecture.
So, it's good, and it's definitely made me more organised and efficient, which can only be a good thing ...