Watts and power

It couldn't possibly have anything to do with amplifier architecture and pleasant soft-clipping. Nope, it couldn't possibly be that. It probably has nothing to do with the rated power at your speakers lowest impedance either.

2 watts of SS power to equal 1 watt of tube power

Instead of starting a new thread, I thought I would drop in a question on these same issues: I've been running a Nuforce STA200 with two 8ohm speakers, horn loaded, so the sound emerges with little effort and the amp runs cool. However, now I'm buying Tekton Moabs and they push a 4 ohm load. The Nuforce is stated to be suited to 8 ohms, not 4. The Moabs are efficient, running at a rated 

• 98dB 2.83V@1m sensitivity

If the speakers run easy, what am I doing to my 8ohm amp, were I to hook them up...?

listening99,

Unfortunately, I could not find much in the way of testing of the STA200, and as you probably know, the marketing literature is very sparse w.r.t. details.  There is this test on AudioScience    https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-nuforce-sta-20...
... which is all done into 4 ohms, and other than fairly high mains noise, nothing looks off. Since you have not mentioned an issue with your likely highly efficient horn loaded speakers, that does not appear to be a problem, but if the Tekton Moab's are a lot more efficient than what you have now, that could be a problem.

Take the comments made by the "reviewer", AMIRM, with a grain of salt. He is the type of "measurements" person, that gives other people who believe in measurements a bad name. His comment

"Looking at the power rating versus distortion, the STA-200 doesn't bring much to the party over the much cheaper Topping TP60 ($199)"

...  shows a lack of knowledge/experience w.r.t. what is important. At low power levels, where almost all music is, the STA200 has much lower THD than the Topping TP60, and considerably lower IMD. The STA200 though clips really hard w.r.t. IMD. With the really efficient speakers, hopefully you won't run into that issue.

Tekton is usually conservative in their impedance ratings. When they say 4 ohms, it usually will not dip much below 4 ohms. I would say you have little to worry about other than what is stated above.

The Nuforce is stated to be suited to 8 ohms, not 4. The Moabs are efficient, running at a rated

• 98dB 2.83V@1m sensitivity

If the speakers run easy, what am I doing to my 8ohm amp, were I to hook them up...?

If you were playing two 8 ohm speakers simultaneously, then the resulting impedance of both together is 4 ohms. If you then expect to play one 4 ohm speaker and one 8 ohm speaker in the same situation, I would check with Nuforce before proceeding as two such speakers in parallel will be 2.8 ohms.