LED tube, reality versus advertised spec

So I bought a LED tube to verify their spec against measurements. The company's web site talks about >100 lumens per watt, power factor >0.9, which are very impressive.

Reality, measured with Kill-a-watt:

Apparent power: 25 VA
Active Power: 20 watts
Label power: 15 watts

Thus measured power factor = 0.80, not the advertised >0.9

With power supply efficiency of 75%(= 15/20), there is no way their lighting efficacy can be greater 100 lumens per watt. Using about 500 tiny LEDs stuffed by hand, their real lighting efficacy would be about 75 lumens per watt, if that much.

As I lower the tube's voltage with a variac, the input power actually increases until the lamp starts to flicker.

My guess is they use a linear current driver, due to the small size of the "power supply", which may be just a linear regulator such as LM317, costing maybe $0.20 in volume production.

BTW tiny LEDs as mentioned in an earlier post, are rated for only 10,000 hours. With 500 of them, their expected life will be much less. I'm returning the tube and getting my money back! BTW Costco sent their LED light bulb PAR-38 purchasers a notice to allow them to return their purchases for full refund, because they also figured out (maybe by reading my blog) that such a bulb can't last 10,000 hours versus 35,000 hours advertised on the package. Indeed, their LEDs are connected in series/parallel combinations, and I don't see any LED by-pass circuit should a LED fail by open circuit.

One thing that bothers me is the narrow light distribution of the LED tube, about 45 degrees. That means I can't use it in my kitchen light where two fluorescent tubes are used. Retrofit both of them will cost over $150 plus labor, therefore I'm reluctant to do it, in addition to my objection to narrow beam pattern, which in all honesty, can be an advantage in many applications.