I know Katona for a long time, treating each other like brothers.
We helped each other on many projects (successful/failed) to gain the experience on dealing with ever-changing SEO tactics, thanks to Google.
He offered to do the SEO work on one of my trophy sites that got hit by Google P/P last spring due to the old BH methods.
We had a good lengthy discussion, exchanging the ideas, etc..on how he would achieve the goal on getting that site.
Based on his suggestion, I and my techs made the major overhaul to that site (in-site SEO), as well as many improvements to the site to make it more user-friendly.
He promised me last spring that he will be very careful as I am interested in long-term, not short-term, as I'm interested in maintaining good organic traffic to that site.
In the last 3-5 months, the organic traffic has increased by 250%. Several high-competitive keywords for that site has been moved from nowhere (page 10) to page 1-2.
Overall, I'm very pleased with his fine SEO work for my site.
He and few other excellent SEO services providers (such as BTB's) are something I can count on to keep my trophy sites humming well.
Please feel free to IM/PM me if you need any references.