Thanks for all the info. Looking forward to visit iceland. Since it's our first visit, we will be semi-tourist doing the ring road. If time allowed, maybe some F road adventure. I will certainly will plan for another trip just for F road adventure and also in depth Westfjord. We are a family that love outdoor and will stay off city vicinity as much as possible. I know the fuel cost is high, but hoping having a diesel 4x4 camper van will get better mileage. Fuel is just part of the expenses. We save on cooking vs dining and camping vs airbnb. This is also our first camper van trip. It's a test to see if camper van fit my need for future adventure.
If you're pressed for time, as in 7-10 days, skip the whole Ring Road. It's best used as a fast route to access better F-roads, many of which are not difficult. I do realize, many rental agencies restrict F-Roads for rentals. Let me put it to you this way. If you just drove the perimeter of America, you would miss Utah, Wyoming, Colorado... See what I mean? If you don't dip into the interior you miss the Fjallbak Mountains, and the vast and raw beauty of the interior.
However, there are some gems just off the Ring. To the south, near Vik, there is a place called Takgil, or Pakgil. It's one of my favorite places to camp and explore in the south, and nobody, nobody, ever goes there. There is also a waterfall to the west of Thakgil, about 2 hours away and just east of Eyjafjallajökull volcano called Axlarfoss. I've been there twice, and not seen another person out there for days. And again, never met a non-Icelander that's even heard of it. It's amazing.
Overlanders are TERRIBLE travelers. They only go from A to B, or point-to-point. In doing so, the always, and I mean with alarming consistency, miss the cool stuff. As the senior editor of Overland Journal it used to make me nuts. Just know, as you loop around the island, you'll miss a lot of the rad stuff people on tour buses, and overlanders, don't see.
Do the F-roads. It's pretty essential to the real Icelandic experience.