Been waiting patiently for MBA decisions...currently have 4 possibilities in the Top 15-20 (have interviews lined up or have interviewed), and on the waitlist spot at my top choice school. The interviews overall have been great so far, been able to visit some of the top schools, hopefully there's a nice triumph sometime this month or next month.
Regarding the value of a full-time MBA, there are some prestige companies that recruit heavily at the Top 15-20 programs. I feel if you want your foot in the door at some highly prestigious jobs and/or companies (say, consulting at McKinsey), have the chance to be surrounded by talented and accomplished people and build your network, and expand your business and leadership skills, you can't beat a Top 15-20. There is no point quitting your job for school for an MBA unless you can get full value out of the experience, IMO. That's the reason why I decided to go all-out into pursuing a top b-school.
There are some elitist snobs who comment in Poets and Quants, who think you have to go to a Top 3 school (Harvard, Stanford, or Wharton), but I disagree with that completely. Any of the Top 15-20 will help you get to where you want to go. It's about finding the right schools for your own career goals, interests, and which school "fits" you the best. Shoot for the schools you'd be proud of attending, and make sure you do your research.