Hi Pete, thanks for your response and I will enjoy, its somewhere I've always wanted to go and have now run out of excuses not to! Im in training for the early starts!
I did the Spirit Of India trip back in 2012 and had the most amazing time. It's a superb holiday all round.
Early starts - yes, there were a few very early ones, but there's no getting around these if you want to see the Taj Mahal at sunrise, or see the sun rising over the Ganges. I'm sure these are experiences you would not want to miss. But don't worry, you may have to get up and get out early to do these things, but come the afternoon you'll get the opportunity to relax by the pool for a few hours and recharge... It's not all non-stop action.
Biggest hazard is the infamous 'Delhi belly'. Take hand wipes/hand gel and use frequently, especially after handling anything (including money). Only drink bottled water. Take pro-biotics. And, I suggest, avoid meat as much as possible when you're out there (it worked for me). You mostly eat in hotels so get a choice of stuff, including vegetable curries and pasta.
You'll have a fantastic time.
Dave