Actually, the USPHS promotes faster than other services. Also there is no don't-ask don't-tell if you're ummm of a different persuasion.
12 years TED & at least 6 months active duty = Promotion to O-4. This means for FP, IM, EM, Peds you are promoted after 1 year post-residency (4 years undergrad, 4 years med, 3 years residency, 1 year experience = 12 years TED). For 4 year specialties you are promoted immediately if you come out of USUHS or 6 months otherwise. Promo to O-5 is another 5 years versus 6 years in the NAVY. The only bummer is that promo to O-6 takes 7 years versus 6 in the NAVY, but in the end you still come out ahead (16 years post-med school to reach captain in PHS vs 18 years in the NAVY)
See for yourself:
http://usphs-ppac.org/PPAC2007Docs/..._Medical_Officers_Coming_Out_Of_Residency.doc
and Page 18 of
http://dcp.psc.gov/eccis/documents/CCPM23_3_4.pdf
Compared to NAVY: NAVY Promotion to O-4 for FP, IM, EM, Peds = 6 years after promotion to O-3 (Start of internship year) = THREE YEARS post-residency before promotion vs. 1 year for PHS, for 4 year residencies = TWO YEARS post-residency vs. immediately/6 months for PHS. Another 6 to reach O-5. Another 6 to reach O-6.
Also, if you take a peek at the officer distribution you will see they are topside heavy, and like it that way:
http://ehopac.org/minutes/EHOPAC125.pdf
There was another site that I had used, but can't find it, the above is a good substitute though... the breakdown is:
33% O-6,
28% O-5,
21% O-4,
13% O-3,
4% O-2.
One other thing that was strange, they call VSP (variable special pay) by a different name: RSP (Retention special pay), though it's the same exact amount.
Lastly, you may not transfer to the PHS from other uniformed services if you have served more than 8 years in active-duty status in another service, unless a waiver can be justified. So for all you armed forces milmed people out there who hate it but don't want to throw away your time in, I hope you don't have more than 8 years AD or you're SOL (though they are debating changing the limit to 12 years).