iMPlayer is frequently updated to fix bugs and improve performance; cracked versions often break after a few weeks.
If you are using IMPlayer, you likely already have an IPTV subscription. The player itself is just a tool. Here is why sticking to the official version is better:
: Unlocks additional theme options and the ability to re-order "Home Tab" sections. Trakt Integration : Ability to sync watch history with a Trakt account. Pricing & Licensing
IMPlayer often runs promotions on their official website. A lifetime license for a single TV device usually costs less than a pizza dinner. Given that you will use the app daily, the cost per view is negligible.