I wouldn't think that the R-value for a trip like what you have in mind would be critical.

1. The major advantage of a Neo air is its small volume (roughly a soda can) when deflated. I have a small Neo Xlite that I use as a torso-length pad on hiking trips.
2. Another benefit is that you can carry an inflatable inside your panniers. It means that your pad will be dry even in you ride or break camp in a downpour (a closed cell will usually be exposed to the elements)

3. There is a very significant price penalty if you choose an inflatable.
4. You may want to carry a patch to repair unlikely but possible punctures.
5. You'll spend a couple of minutes every day inflating/deflating

6. I was worried about the bag-of-chips sound that comes form the neo-air if you toss in your sleeping bag. I either got used to it or it actually gets fainter over time. Not an issue for me

As far as I am concerned, the critical variable is volume. I prefer the neo-lite.