The Sloan Fellowship program was run out of 3 campuses - LBS, MIT and Stanford. Starting this year, Stanford has moved away from the Sloan branding and started calling their program MSx- http://www.gsb.stanford.edu/msx
I believe the content of the program remains the same.
As you have figured out, these programs are for senior/ mid level managers with considerable work experience, about 10 years and more (Stanford requires 8+ years). They are ideal for people who are expecting a career acceleration to the senior positions, withou much change in their industries or functions. For this reason, a lot of candidates are company sponsored. This is the key difference between the regular MBA and the Fellows programs. They may follow an integrated teaching approach (lecture, case, team based, simulations, experiential...you name it!).
Placements- As I mentioned, many candidates are sponsored, so they get back to their companies. I know the case specifically for the Sloan Fellowship at LBS, so I will mention that here: You can take part in the recruitments for the 2 year MBAs, but a lot of these job postings may be at a lower level. Not matter, you can still consider it an opportunity to meet the companies and discuss unadvertised lateral openings.
On another note, you can consider a few other programs based on your needs: the PGPMax/ EPGP offered by various campuses of the IIMs, and the fellowship program offered by NTU in Singapore, which targets the same profile of students as the Sloan fellows program.
European b-schools like INSEAD, IMD, HEC Paris etc. are more open to older applicants, so keep them in your consideration.