"... Overall [Tiger Hillarp-Persson] gives you much more content than the average opening book. However, this makes the book less accessible to the average player, who may not have the patience or aptitude to understand the material. Yet, if you’re willing to put forth the effort and if you like exciting chess and unusual positions with plenty of dynamic play, then this book will serve you well. ..." - FM Carsten Hansen (2005)
https://web.archive.org/web/20140626230719/http://www.chesscafe.com/text/hansen79.pdf
"... I feel players from 1600 to grandmaster can get a lot out of this book. Without a doubt, it will be a tough road for those under 2000 at first, but the author’s plan-rich explanations (some of the best I’ve ever seen!) make mastering this system doable. …" - IM Jeremy Silman (~2005)
http://www.jeremysilman.com/shop/pc/Tiger-s-Modern-76p3693.htm
https://www.qualitychess.co.uk/ebooks/TigersModern-excerpt.pdf
"... Persson has taken a fresh look at nearly everything in the earlier book, added over 40 new illustrative games and, perhaps most valuable of all, added a sense of perspective that comes with an additional 10 years at the forefront of the battle for acceptance of these black ideas. … the sheer depth of the analysis provided – with hundreds of additional game fragments and analytical suggestions included within the 102 illustrative games – over its 536 pages is staggering. ..."
http://www.jeremysilman.com/shop/pc/Modern-Tiger-The-76p3901.htm
https://www.qualitychess.co.uk/ebooks/The_Modern_Tiger-excerpt.pdf
You are very lucky. I have never played anyone above NM in OTB.