The Kayfun Lite Plus and Russian 91% are so much alike, it is hard to make a choice... For me, I selected the Russian based on air-flow screw location. Although, honestly, once you set the air-flow to where you want it, you'll rarely adjust it, unless you change to a thicker/thinner juice.
YiLoong makes really good Russian clones. I have two of theirs, and other than being a few mm taller than the authentic (which I have two of), their performance is spot-on. The best part is that you can pick up clones for < $25. Kayfun clones can be found < $20, but I would avoid the no-name cloners and some people say the Tobeco clones are hit-and-miss in their quality/performance... I wouldn't know, as I don't own one. EhPro seems to be one of the better Kayfun clones... Infinite and HCigar also make good ones, but it's hard to find an HCigar V1 or V2 these days.
The authentic Russian is made in China at the Kebo manufacturing facility. They also make clones in their off-contract time, so yes, there are 1:1 clones out there, made on the same line as the authentic, but without the UCT logo between the air-screw and air-hole. Any clone listed with a body of 42mm and overall height of 72mm would be a Kebo manufactured clone. YiLoong clones are 47mm body and 78-84mm overall height... because they use also manufacture Kayfun and use the same chimney and body-tube sections for both... the YiLoong clones hold about 0.5ml more juice than the authentic, too. One thing to look for when buying a good Russian 91% clone is the logo/lettering on the base... The YiLoong clones will have "The Russian 91%" spelled out in lower-case letters, and the first letters, "T" and "R" will be oulined letters, not solid-block letters. The last letter "N" should be an upside-down "U", not a typical lower-case letter 'n' with a visible straight line on the left-side...