It might be interesting to know that I had to ban a handful of SEO/backlink checker bots from my site. They were pounding so hard on the server that I was almost put in the penalty box.
- Barkrowler (exensa.com)
- MJ12Bot (mj12bot.com)
- AhrefsBot (ahrefs.com)
- AlphaBot (alphaseobot.com)
- SemrushBot (semrush.com)
Be prepared to have to deal with obnoxious bots that swamp your server and make you use too many resources (e.g., accessing a new page every second, even before the previous half dozen pages were finished). The listed ones were banned (except for reading robots.txt), and robots.txt in turn disallows them.
I'll just have to do without their reports (most of which are $$).