I'm almost to Ulysses' Temple & know that there's a choice to either find & release Ed-E or continue without him & get the Lonesome Road perk. Is the perk valuable enough to finish the quest without Ed-E, or should I just get my robotic BFF back? I'm leveled-out & all my skills are 100. So unless the perk gives me a decent combat advantage, I'd rather have Ed-E during the final fight beside me & Ulysses.

I believe you can get one of a few perks depending on your actions in Ulysses Temple. Check the wiki if you need a full list.