At the risk of being branded a heritc or worse a pariah,,,, I'll offer you my thoughts.
I have found the EN-EL15 battery more than adequate for my shooting needs. As long as I remember to charge it the night before a heavy shoot, I have only once run it low to the point I was worried.
But when I bought my D80 I quickly found having a second battery was a must. When I went to the local B&M to buy the Nikon EN-EL3, the rep recommended the Promaster replacement. It boasted a 2500mah rating compared to the Nikon 2000mah and was cheaper. At first I was hesitant, but the rep assured me its was every bit as good and backed it with a money back if not satisfied. I have since handed all my D80 gear to the granddaughter and some 5 years later the Promaster battery is still plugging along with the Nikon battery without issue.
I'm not familiar with Lenmar, but looking into them, they seem to be a global reputable company. But looking at their replacement battery, it's only 1750mah compared to 1900mah Nikon. So to me the $9 difference is eaten up in available power rating, so in that case it would seem to be a wash and I personally would choose the Nikon.
But I would stay away from the e-bay sub-$20 no brand name specials for many of them are junk.
Just my 2 cents as I put on my flame retardant suit!!!