Wouldn't it be better to just glide the booster back down 
Wings or a chute?
Wings would mean a tail, control surfaces, hydraulics or electric actuators, landing gear... a runway. And we're just back to a variant of the Space Shuttle which didn't work out too great in the savings department in the first place. And IIRC, all the early Shuttle concepts had an aircraft shaped horizontal landing first stage booster with the shuttle piggy-backing, and for whatever reasons, technology of the day, or maybe just practicality, it was ditched.
I think the weight penalty of wings kills the advantages. The direct tail-landing re-uses the same engines that launched the rocket in the first place. So at least the engines are "pulling their weight" and doing useful work both on the way up and the way down. With wings and a glider first stage, the wings are dead weight and useless on the way up, and then the engines and their turbopumps are useless dead weight on the way down.
Chute landings are still pretty rough and uncontrolled, and you can't control which way the booster stage lies when it touches down either, so I'd think that needs to be a water landing like the Shuttle SRB's. Then everything needs to be waterproofed, or refurbished after exposure to water, a collection vessel needs to be set up, the docks and the cranes to lift it back up etc.
The (barely) reusable shuttle SRB's weren't all that much of a savings either. Especially if once considers their design was the downfall of the Challenger.
