My quick thoughts on each candidate.
Mike Holmgren-A coaching great, a Super Bowl winner, great with QB's and a local guy. The downside is that he's 67, has been out of coaching for awhile and I don't know how strong the motivation is to put in the ridiculous hours that being a head coach requires. He seems interested according to various reports, but guys with that lengthy of a layoff from coaching don't often tend to do well.
Pep Hamilton-The Colts offense has been explosive, Hamilton has done a very good job in utilizing the various pieces of his offense. However it has not been a very balanced offense, they obviously lacking talent at RB but it leaves one to wonder whether Luck is more responsible for the success that Indy has had than Hamilton.
Adam Gase-Definitely a favorite of mine, has had some highly successful people vouching for him, is seeing as one of the top head coaching candidates going into 2015, could have had a job as a head coach in 2014 but turned it down in favor of more seasoning. Has shown he's very flexible in his approach, having coached Tebow and helped adjust the offense for him as well as having earned the respect of Manning for his offensive creativity. Young coach and just as with Hamilton, there's questions about whether his success has more to do with the quarterback running the offense than him.
Gary Kubiak-All in all this this might be the best, most balanced candidate IMO. Was the QB coach on the 1994 49ers Superbowl team, recognized as having a tremendous offensive mind, his work with Baltimore as their OC has been outstanding. Their offense is ranked in the Top 10 of the NFL for the first time since 1997. A Ravens OL that was one of the worst in the NFL last season now all of a sudden is among the best in yards rushing before contact(3.1) and a low amount of sacks. Flacco is thriving and Justin Forsett has looked beastly in Kubiak's zone blocking scheme. Has head coaching experience, but isn't super old, only a few years older than Harbaugh was. Well experienced guy who has won Superbowl's as a QB coach and an OC. In the event that the 49ers were to lose Fangio, Kubiak could have Wade Phillips on deck to be the defensive coordinator. Issues to look at would be what changes he would make since things fell apart with the Texans and especially to look at health related concerns. But all in all, Kubiak presents the fewest concerns in my mind and from top to bottom would be dealing with a better roster than he ever had with the Texans.
Vic Fangio-Seemingly the most popular internal candidate from these forums. A tremendous DC with a lot of coaching experience. Respected by the players and could probably keep most of the defensive staff intact. The familiarity would still remain as Fangio has been here for the entire Harbaugh era making for perhaps a much smoother transition. The downside is now that you need to find a quality OC and be at that person's mercy essentially the same way Nolan was.
Jim Mora-He was brought up in a few places as a guy that would be interested perhaps in the 49ers making him an offer. Was a DC with the 49ers for quite a few years, also has head coaching experience in the NFL. Not a guy I'm real thrilled about but someone that has been brought up enough times to warrant consideration here.
David Shaw-Seen as a popular choice, local guy, much more affable and media-friendly than Harbaugh is. Experienced coach that has been around a bit but the downside is that he's been criticized for similar struggles as this offense has had, scoring in the red zone....etc. I think his hiring would largely depend on who he brings to the table as an OC.
[ Edited by Phoenix49ers on Dec 17, 2014 at 9:13 AM ]