I've been to MP three times and we visit Lima yearly. The Tambo is a very nice hotel. I've stayed there once for five nights and enjoyed it. That said, it is a bit secluded and feels more like a retreat. I guess it depends on the type of trip you are looking for. My suggestion would be to spend five or six nights in Cusco and make it your hub. You can take the early morning train from Cusco and do MP in one day and not feel rushed. I'd then do one or two private Sacred Valley tours with an English-speaking guide. There is one tour that takes place just outside of Cusco and then a Cusco city tour. There is just so much to see, do, and eat in Cusco that you might miss out on staying at the Tambo.
I'd also recommend looking at the AC Hotel that is in the Marriott chain and has an amazing ocean view. It is also next to Larcomar and it is typically a better value than the JW Marriott (which I believe is aging on the inside). Feel free to reach out if you need any tips on what to see in Lima or where to eat.
