I have posted about this in similar threads. First, my entry into flashaholism was a Coast Lenser Tac-Torch. I was impressed with that light because my previous exposure to LED flashlights was with 5mm single and multiple LEDs. The Coast was a vast improvement over them. I paid about $60 for it. It was the first time I spent more than $20 on a light.
I believe the reason that CPFers arent' impressed with the Coast product line is threefold.
First, they appear to be marketed using slick technobabble to people who have no clue about LED flashligts. That insults the intelligence of those who do know. This hurts Coast's credibility among flashoholics.
Second, They (generally) are overpriced for what you get. My $60 tac torch is nowhere near the quality or capability of even some $25 Chinese lights. It is huge for a light with its capability and battery capacity.
Third, the 3 x AAA battery carrier is disliked by many CPFers. Aside from it being cumbersome and awkward, I don't know why this is.
My Tac-Torch doesn't suck, but the general consensus around here is that you can get a much better light for the money.
That said, I looked at
THIS review of the focusing Lenser. It directly compares it to the Streamlight PP 4AA, so that should partially answer your question.
I have to admit, it looks to perform pretty well, and it does something that very few lights do well: spot to flood-focus without nasty rings everywhere. It seems kinda steep for a Coast light at around $50, but I don't know of another LED light that can do that for anywhere near the price.
I honestly haven't seen the Nuwai X-III discussed much here either. I'd say that it's not one of Nuwai's better offerings.
You probably won't regret buying the Coast, but it is certain that you are or will be smitten with flashaholism. That dictates that you keep buying better and better lights, or at least modding the ones you do have.
Bernie