I have not been able to find any way to download an trial copy of the single-user version of Lightroom 6 as I am considering upgrading from Lightroom 3. I have been very frustrated with Adobe's push of everyone to using CC and that is the only trial license download I can find. Is there an option or is CC the only option for a trial license. The only option I can find that was listed earlier takes me to a buy only single user option.
I am frustrated with Adobe and get more and more so the more time I spend on their site. I am giving serious consideration to DxO OpticsPro ELITE Edition as an alternative to allow me to import raw files that are not supported in Lightroom 3 which is my main driver to go to version 6.
The only trial version is the creative cloud version. However, if you decide you want to purchase standalone Lightroom 6 there are instructions to enable you to convert the creative cloud version to a standalone Lightroom 6 version. Doing so will cause you to lose a couple of features, and you will not be able to use Lightroom Mobile anymore. But you will have all the functionality Lightroom 6 has to offer.
I believe the thinking by Adobe is that they want to give you the opportunity to evaluate the power of having both Lightroom and Photoshop (up-to-date versions) so that you can see all of the potential that is there. But you are certainly free to convert to standalone Lightroom if that is your choice.