Extension agents are probably as varied across the country as other people are. Times have changed: No longer do we see the extension agents always willing to drop by the farm or ranch, sit a spell, chew on a straw while discussing the real issues of one's program, and offering valid sage advice or suggestions.
My (limited) experience with EA's has been that the farm & ranch component of the County Extension Offices has taken a back seat to the more "popular" programs of 4-H, Domestic Issues, and such. Also, I think quite a few extension agents are just out of college with an Ag Degree and primarily know the academic side of agriculture, but not the local conditions and issues at the post to which they are assigned. Some of the same issues are also present with new Vet graduates who larger numbers are prefering to go into "small animal practices" (more $$ and cleaner, safer work).
In all probability, if one can find a local farm/ranch mentor who is willing to share his/her knowledge (without feeling threatened by the newbee), that is probably the more valid and useful choice with whom to consult rather than the County Ext. Agent. IMHO.