Nice job Eltehs.
I build and sell/install MR16 conversions locally, though I haven't gotten into active cooling with the Nuventix coolers yet. I prefer passive and very efficient setups. Spending more on LEDs and reducing current across them to reduce heat and gain higher efficiency, though, 1200 and 2000 lumen would not be possible with this technique.
Using the latest XPG warm white Q5 LEDs X3 running at 350mA I get over 100 lumen/watt. After driver conversion it's still high 90's, for warm white! Heatsink temps are 40-60 depending on ambient temp and airflow in the room.
Over 300 lumen each, they fall right in between a 35W and a 50W MR16, and work great for replacing either.
I also like using 4000K R4 neutral LEDs to achieve nearly 400 lumen per MR16, passively cooled, wonderful colour rendering, and well over 100 lumen/watt even after driver loss.
An LED driver is installed in the junction box for the fixture, usually I find myself doing 3XMR16 fixtures, running all LEDs in series for maximum driver effiency requires rewiring the fixture to run in series, and you also have to mark + and - on the socket to insert the LEDs the right way. All pretty easy stuff with basic electronic knowledge.
End up dropping a 150W fixture to ~10W.