I am thinking about getting the UP by Jawbone

The UP is a great piece of kit. The app will give you all sorts of info on your daily activity and sleep quality for a given day, and tends too.

If you were just using UP then you can also use the app to log food and exercise - BUT (and it isn't a big one) as you're using My Fitness Pal (MFP), then it is best to continue using MFP.

When you link the accounts (don't forget to tell MFP to allow for negative adjustments), info on food goes from MFP to UP but not from UP to MFP.

Excersize goes from MFP to UP but not from UP to MFP.

Activity details go from UP to MFP.

So, log food in MFP - it shows in both apps and the database in MFP is far better.
Excersize: Make sure when you add excersize you enter the time correctly (ie 1pm for the lunchtime walk). This helps the +/- calorie calculation done by the two systems. So the UP doesn't give you extra credit for a run you entered into MFP if you wore the UP on the run, or doesn't tax you for not been active while you were swimming (UP is not waterproof) even though MFP gave you credit.

When you sync your UP with the app on your phone, you'll see an adjustment appear under exercise in MFP. If you sync first thing in a morning (say to see your sleep data), you'll notice that the UP has taken calories off you because you haven't been active enough for the day. That's fine because if you then sync again at tea time you'll see it changes.

I like that because if I haven't been active enough, I am taxed calories. MFP guesses based on your info how active you are and thus how many calories you show eat. The UP KNOWS how active you are - there's no hiding the fact that you've been sat at your desk all day and didn't go for a walk at lunch time...

If this has made you go what?!! Or you have any questions please ask. It isn't a bad as it sounds, in fact it is simple. There's just a couple of things to watch for, but why work it out for yourself when you can ask.