I prefer 4" because it's portable, and blue because the blue finish on a 29 is S&W's best. I think the 4" blue 29 is S&W's classic best. However, you should know that my opinion is nearly worthless - I proudly show my 4" 29 with Pachmayr no-medallion SN-S Presentations. I think that the stock target grips **** *** ****** *****, and the "Goodyears" are the best of the grips contemporary with the early 29s.