I have them both. I like my ruby red Touch Lux 5 cause of the different color to usually black devices but would recommend the Kobo Clara HD. Kobo Clara HD has 300 ppi vs. 212 ppi by Touch Lux 5.
If you want to read with Standard Software out of the box, in my opinion this is another PRO for the Clara HD, KOBOs Software offers more setting options.
I don’t know where you are located, right now there is a special offer for KOBO Clara HD 89,99 $.
Kobo Clara HD - 89,99 $