I studied a bit of the Uyghur & Uzbek languages, both of which are apparently the 2 closest modern Turkic languages to Old Turkic. But, I didn't study either language for very long & didn't advance much. I can only point out a few words from the text.
I really like Turkic languages, except for 1 thing: rounded front vowels. The vowels [y] & [ø]/[œ] are just so unnatural to me & I have trouble properly saying them, especially [ø] & [œ].