Alrighty then! Here's a tale from my own experience wiht those two powerhouses. I tried both SEMrush and Ahrefs in the past year to boost SEO efforts on one of our sites - an e-commerce platform selling vintage records (<
https://vinylmuseumstore.com>). While they were equally helpful, there was a clear winner for me:
Ahrefs. The Site Audit tool helped identify and fix technical issues that SEMrush missed out on initially; the Backlink Analysis also provided more accurate data about referring domains (something I found important in my niche market with fewer links). I'd recommend checking them both, but if you want a head start-try Ahrefs first.