First, full disclosure: I'm an avid beta tester for Chaotica, but I guess that just puts me and you on the same footing bias-wise.
Second, apologies in advance for what will probably turn out to be a wall of text. I'm a thorough person by nature and I think in paragraphs, not quips.
I think part of the issue here is that everyone talks about "high quality" images without ever explaining what exactly they mean by that. To me, high quality means smoothness of anti-aliasing (no jaggies), while retaining an overall sharpness that lets details and textures be seen. These two concerns can be surprisingly difficult to balance! After that, I value an absence of grain, although this of course is partially determined by rendering time and not quite as program-dependent as the aa... but, since grain is occasionally unavoidable or even desirable, we should lastly take into account that some programs just seem to have much more attractive and "natural looking" grain.
With that in mind, the google plus image you've linked does not particularly impress me, sorry to say. The extent of the visible jaggies almost reminds me of a photo that has been over
sharpened in photoshop or something like that. The grain in the background, aside from being very prevalent and unsmooth to begin with, just looks... very harsh. I have similar issues with the example images on the fractalarchitect website.
To this I would contrast...
But, for a more one-to-one comparison we really should use the same params. I think these http://pastebin.com/gEjDxUS4
would be good; they are fairly simple, no plugins needed, etc. But if you want we can also compare with any flam3-compatible params you have.
It's not that I think the intuitiveness of the interface is unimportant, but to me, if I can't use that interface to generate a nicely sharp and anti-aliased image, then... the user-friendly UI is almost wasted. I realize this is a personal opinion, and especially if someone is a new user they might not be so fussed about jaggies and grain and whatnot, but my point is that a solid rendering core and high quality image processing is more substantial and fundamental to a fractal renderer than a flashy, "inspiring" interface, especially for a longtime or serious user. It seems to me that newer users are often easily impressed when they can quickly churn out colorful wispy designs, but after years of making fractal art and looking at literally thousands of renders, I am quite inured to hyperbolic claims about "blowing anything else out of the water" which are then followed by the kind of aliased, julian-based, semi-randomly-generated mandalas that I've already seen hundreds of times before.