LED MR16 replacement bulbs: How to evaluate brightness and color temp?
You're looking for subjective human-opinion reviews.  However, the questions you are asking about are measurable scientific facts that are labeled on almost every bulb, and certainly any bulb legal to sell in the United States. 

Lumens

The useful light output of a bulb is in lumens.  This is a measurement of the light that you can see, and the wedge that it is lighting up.  

You must factor for the wedge angle of the bulb.  If you have a 120 degree angle bulb that is the brightness you like, and you want to switch to a 60 degree angle bulb, that will illuminate 1/4 the area, and will land all its lumens in that 1/4 area, So that area will have 4x the lumens hitting it.  That will make it brighter, not 4x brighter since light is a decibel curve. 

Color Temperature

Color Temperature is the color of the light, which you call "coldness".  Normal halogens are 3000K.  Office fluorescents are 4100K. The early LEDs that were popular prior to 2015, especially the cheapies, are typically 5000-6000K because those are the cheapest lumens per dollar. LEDs have gotten quite good and you should have no trouble finding 3000K LEDs at sane cost, for most applications. 

Read a more detailed examination with illustrations here.