I was a tarp-and-bivy user 15 years ago, when there were no really light tents available. (tarp and bivy: 3 pounds; tent, 5 pounds.) When MSR came out with the Hubba, which weighed the same as my tarp and bivy combo, I switched and never looked back. My current favorites are two by Big Agnes: Fly Creek UL1 at two pounds (or Platinum 2, if you survive the sticker shock, same weight), and the Copper Spur UL 1 at two and a half pounds.

I like tents that have all-mesh bodies; without the fly, it's just like sleeping under the stars. (Big caveat: I hike in the East Central states of Ohio, Kentucky, and Indiana, where winter is mostly temperate, and I rarely go out if predicted lows are below 20. If you don't hike in such mild conditions, the all-mesh body may not work for you.)

Solo tents can be a bit tight (I've seen the Solitaire you mention, and it's a good bit tighter than the Fly Creek), so before you commit to one, you really need to have your technique refined to be working with minimal gear. Otherwise, you may find that a solo tent is just too small.