"Really? How far into Israel have they gone?"
Missiles have gone many miles. Nasrallah threatens Tel Aviv with militarily insignificant missiles, the Israeli government makes all sorts of noise showing the terror works.
How far did Israel go in 1967 against big armies?
A victory for Hezbollah so far. Relatively. This smells like Fallujah 1 when Bush didn't pull the trigger and stopped the attack. That emboldened the Sadr, Sunnis, many others to increase terrorism and attacks. All they understand is balance of power.
Saying that Hezbollah is kicking Israel's asses seems a lot like saying the Germans were kicking the Allies asses on the beaches of Normandy, except the Allies were actually taking most of the casualties, IMHO. Those Hez rockets and missles seem to produce zero tactical results, again...IMHO. Is there any doubt in your mind that the Israeli army can eliminate this foe if allowed to continue? I really don't know enough about the Israeli armed forces.