Hi ...
First, I do not consider that I am an accomplished renderer. I have Blender, Octane and SimLab Composer but little real expertise with any. I just tried the free/lite version of Owlet and I am impressed. It is intuitive and fast. I got a reasonably good, illustrated render of a small cabin with about 15 materials in about five minutes without reading any tutorial material. I just opened it, loaded an obj file and began changing reflectivity, colors, shades of materials, etc. It only took seconds to respond to change and to produce a pretty good and clean image. The other tools are very good in my limited estimation but I am tempted to buy this one for quick illustrations of architectural models.
cheers,
eric

I have been working with Owlet and SimLab Composer today ... I had some problems with Owlet making holes in large solids (like the ground plane) and when all the materials were applied the render time is pretty slow. If I had to make an evaluation today ... I'd give Owlet a 5.5 out of 10 and SimLab an 8.

It is probably not a fair comparison. I was using the free version of Owlet and the Pro Version of SimLab.

cheers,
eric