I've been travelling and use my 5 with an overseas sim and have a 6 as my Aussie phone. I actually really like the form factor of the 5. It's getting on a bit so a bit slow but for the odd email, phone call, SMS and web search it's been really good to use for the last few weeks. It feels good in my hand.
The 6 is getting a bit slow, after a 3G, 4, 5, and 6, the 7 was the first non-S I didn't buy at launch. I'm seriously tempted to upgrade the 6 to the SE even though it's not the latest phone, but will wait until the announcement in a few weeks, as the SE should still be available for a bit after that if nothing in the new lineup excites me!