The birmingham Hip is a great advancement. Younger patients are able to utilise the technique, with much reduced risk of leg shortening. Revision later in life may require a total hip, and further revision if it fails in 10 - 15 years, with all the associated risks.
Patients may have more pain with a Birmingham resurfacing, as the amount of muscle cut to do the operation can be greater than with a total hip. Access is more difficult with a Birmingham, as the femoral neck and head is preserved, requiring a dislocation.
Overall, following initial increases in pain, patients recover function more fully. Hope this helps.