I have an A8 clone from eBay. I was totally underwhelmed with the overall quality, fit and finish, etc. Besides fit and finish issues, I had contact issues with the tail switch assembly that were a pain to fix. I replaced the driver and maybe put the LED on a Noctigon, I don’t remember - the result wasn’t impressive.
The F13 from GB isn’t a bad light, but out of the box it’s not very impressive either. I replaced the driver and installed an XM-L2 on a Noctigon and used a thin centering ring. I ended up with a huge spot, I think I may warm up to it. Other people seem to like it.
I don’t have one, but for superior fit/finish/build-quality, maybe consider the Supfire L6? Supfire L6 Update Version LED Cree XM-L2 1100 Lumens 1*26650 or 1*18650 Battery from DHgate Farfar_ledtorch
I’d stay away from those eBay lights if you’re looking for quality or a sure thing. Stick with a trusted or semi-trusted dealer and a model that’s known to deliver consistent results. There’s little to nothing you’ll be able to key off of in an eBay listing to “detect” quality.