When I wear my red shirt, I prefer the Widowmaker, when I wear blue, the Solus.
Ok, both of these kites are incredible and you won't be disappointed with either one. The Widow Maker is one of my all time favorite kites, I own 4 of them. It is smooth and incredibly forgiving. Tricks are precise and the control through the rotations is steady and consistent. I have been flying my Widow Makers for a couple years now and still learn new things on them. They can do much more than I am capable of doing. I don't think you will ever grow out of them.
The Solus is a large wing that flies like a 3/4 stunter. It has the same characteristics as the Widow Maker and is also more capable of things than I am a pilot. The Solus excels in short, fast hand movements. It is quick on the tricks while being large and precise on the eyes. It pitches much quicker than the WM does which allows for insane roll-ups and even milti's. For a big winged kite, it pitches exceptionally well. Turns are sharp and precise but you need to make sure your hand skills are up to par. It is more sensitive to inputs than the Widow Maker but once you get your timing and hand controls down, this is a super fun kite to fly. It corners ultra sharp and punch turns are fast and exciting. Straight lines are clean and direct.
Both of these kites have an incredible wind range, standards can easily fly down into the 4mph range with nearly zero work. With skills and foot work, you can fly them into the 3mph range. The UL's can fly down to 2mph with little foot work and can hit into that 1mph range if you want to do some serious foot work.
As for suggestion....
It kind of depends on your flying style as to which one you would like best. If you want a faster pitching kite that tracks very well and uses shorter aggressive inputs, the Solus is a very exciting kite to fly and it rocks. If you want a kite that likes sweeping hand movements and smooth forgiving control, the Widow Maker is one of the best kites you can buy.
I wouldn't be upset if I was stranded somewhere with either one of these kites.
It really comes down to what colors and panel layouts do you like best??