Simoahava has a rating of 5 stars from 1 review, indicating that most customers are generally satisfied with their purchases. Simoahava ranks 56th among Web Analytics sites.
Simo Ahava is by far the best expert on Google Tag Manager. He covers even the most technical topics very thoroughly, but accessibly. You can bet if you've got a problem with Tag Manager, Simo likely has a resource to at least put you on the right track toward solving it.
Simo is also very interactive with comments on his conent.