Can't decide which one to go for over NY period.Both seem great.Can you help me decide?

You are right - Both are really great. I personally would choose the Scotsman - I love the location and have sentimental connections. But that choice is really subjective and I would not turn down a stay at the Caledonian.

Which ever one you can get in you will enjoy.

For the New Year period (when I will be in Edinburgh myself!), I would pick the Caledonian. It has fabulous views of the Castle and Princes Street and, therefore, the fireworks, though you very likely will be somewhere on Princes Street at midnight.

I'd pick the Scotsman because I've never stayed there. But the Cally has more cachet. It's betetr located for shops and restaurants and less well located for history tourism

Thanks for your replies so far butI am still undecided.I've noticed that most hotels around the NYE period are charging inflated rates ie room with six course meal etc @ £400 per person;they will not release rates for room only until nearer the time.Is it best to wait?

The only times of the year Edinburgh completely books up are during festival/tattoo in August and Hogmanay (new years). It is one of the largest New years parties on earth. They charge £400 because they can get it. If you wait too long you may not be able to get in at all. If you want to spend less you might want to look at other properties - but most will be doing packages over new Years.