I have an se pro and have no troubles in most types of soil, but there is a certain type of loamy clay that you seem to find here in texas in areas that have been used for cattle grazing for long periods of time even if its not recently. It turns the ground into this hard thick stuff that is almost like digging in wet slightly decayed wood. I would swear that my machine simply can not see through this stuff and whenever I get into it I know I won't dig anything deeper than two or three inches. Am I crazy or has anyone else experienced this? Any insight?