For reference sake - it might reduce a lot of Q&A if there were a table including (1) the features of each theme, (2) which ones are known to be easily transferable;
To some extent, we have an embarassment of riches - but it's still hard to make choices.
But to the extent features are transferable it makes the whole Justin "system" more systematic and modular. Further - if color choices were similarly modular - the number of theme permutations would increase geometrically. Just a thought - and I'm not wedded to it - it occurred to me when I thought Spartan was brilliant, tested it - and got feedback that the red seemed discordant with that site's subject matter.