To rent a 4x4 small car is about 740 € (2 weeks) vs a small compact that is just 260 €. I have some experience driving off-road and I know that a "normal" car cannot go through some f-roads I've seen in pictures. In the other hand, my budget is limited, so I'd like to know if a 4x4 car is really a "must" in end of April. This question talks about a similar topic in August, but I expect a very different weather in April/May. There, the accepted answer states:
You do not need a 4x4 on "normal" roads. If you plan to stay on the primary roads you can get by fine without one
It's still true in April?
Of course I want to have access to every tourist attraction (Geysir, Gullfoss, Vatnajokul, Landmannalaugar, Jokulsarlon...) and it could be very frustrating to not visit a sight because we cannot access to it. In case that only a couple of interesting sights were impossible to visit without a 4x4, if there is an alternative (public bus for instance) it will be ok for me and will rent the non 4x4 car.