I think I am a bit like you and worry a lot when on a hike, especialy about the weather :-) I know its a bit strange for a hiker who wants to be in- and enjoy nature, but who's constantly worried about the weather, but that just how I am I guess...
Now, I'm still in doubt regarding the choice Unna, Soulo or Rogen. As my iceland hike is only in july I will have the opportunity to await some reviews of the Rogen. I will decide then I guess.
I understand your choice for the 4-season Unna that can handle almost every weather-type, but as I am a young guy and not working for a very long time I have only litlle savings that should be spend wisely (especialy at those Hilleberg-prices :-) ) I've never done a solo hike (and nor will I in Iceland, but I go with 2 friends who will share a tent) and I'm not so sure if I will do it a lot in the future.
That's probably my biggest concern if I should buy a solo-tent, namely that I wouldn't use it enough to justify the price.
I'll probably buy a 2-person tent I guess. The Allak looks perfectly but is very heavy when I have to carry it alone (3,1 kg). The Rogen looks like the ideal compromise, not to heavy to carry alone (2,1 kg), and I can also use when with 2.
Doubts, doubts, doubts :-)
PS: I want to thank everybody for your numerous and well-founded replies! I'm very glad I found this forum today! You've already helped me a lot!