Istanbul and ?
 

We will have 5+ days in Istanbul -- would you recommend staying in Istanbul all 5 days (first time there), or taking a day for a day trip to Cappadocia?

You'll find that 5 full days in Istanbul, especially for your 1st trip, will allow you to only scratch the surface of that beautiful city. There is the Old town, New town, Galata Bridge/Tower areas, the Grand Bazaar, Spice Bizaar, the Bosphorus cruise, a trip to Asian Istanbul, a cruise to the Princes Islands, and everything in between. If you are interested in a day trip out of Istanbul, and this would be a very long day, consider going to Ephesus.

Get yourself a good guide book (found Rick Steve's to be especially helpful, especially while on the Bosphorus cruise) and/or consider downloading the Fodors city guide to your iPad if you have one.

If you're interested, visit a MODA store for a delicious ice cream treat! There are several locations scattered throughout Istanbul and one on Princes Island.

Cappadocia is a long way for a day trip. With time to travel there, presumably flying, I think you'd want to stay 2 nights to have a full day there.

Alternatively, the Prince's Islands are not far from Istanbul by ferry. I stayed overnight on Buyukada, very tranquil, no motor traffic except some small municipal vehicles, otherwise horse carts and bicycles.
http://www.turkeytravelplanner.com/g...Sights/adalar/

Thanks - it certainly sounds like we should just stay in Istanbul, and avoid the stress of the day trip on this trip. We'll be back and do more on another trip.

Stick to Istanbul and a Bosphorus ride. We also found the Rick Steves book very useful. You might want to take a look at my trip report; click on my name to find it.

Yes I also second the advice of staying at Istanbul and really explore this amazing city at your own pace. I love to take the ferry and venture out to the bosphorus, there are lot of tiny village waiting to be explored by those who are adventurous.