Maybe I am just too spoiled by the supernatural aspect of the Barnabas episodes that I so much prefer them. The supernatural escapism was what drew me to the show, it made it different from other soaps at that time and most soaps from this day and age as well.
Not saying the pre-Barnabas episodes were bad, having watched them the first time a few years back on the sci-fi channel I actually found much to enjoy (I especially liked the Laura story and who killed Bill Malloy plot). But until the [spoiler]Bill Malloy's ghost appearing to Vicki, then Josette's spirit stepping out of the portrait)[/spoiler] DS seemed liked just another typical soap to me.
Once Barnabas came, the show really picked up speed.
I have to agree though, as much as I love Barnabas and the supernatural stories that came along, unfortunately some of the characters did get pushed to the background. Roger for instance. I agree he was much more prominent and better used in the pre-Barnabas episodes than he was after Barnabas came along, which is a shame because he was a blast to watch when he was being all pompous. Elizabeth's character did seem to change also with Barnabas' arrival, she was definitely a lot more strong-willed at the beginning of the show, and she did seem to lose some of it especially after [spoiler]Cassandra put a spell on her, making her obsessed about death and making her believe she was Naomi.[/spoiler]
The one thing I would have changed about the Barnabas/supernatural episodes coming into more focus was give Roger and Elizabeth more airtime. Someone already suggested that David's parentage should come into doubt, and that would have been a good one to showcase Roger [spoiler](and have the results prove that Roger is indeed David's dad).[/spoiler]