Are Sir , I have seen this difference . I have traveled in SDAH Raj in 2005 which had excellent service but in my HWH Raj (via PNBE) journey this year , I have found that it's services have deteriorated over the years . My last trip in 1998 in HWH Raj (via GAYA) was far better during those days . Rajdhanis are the Main Trains for any Zonal Railway [and it's Division(s)] . Looking at the Raj Services I can tell you that I am disappointed with this partiality between HWH & SDAH Divs . Come to Calcutta once and ask the people over here , you will then get to know :)