Which portaledge? I believe the eldo is too long to fit completely on all ledges on the market.
I have a custom BD I tent that they made specifically to fit the BD double skylounge (floor zippers, reinforcements, tie in point, etc etc) and it barely fits on the ledge.
As far as the two tents go I have spent most of my time in Bibler tents... no complaints... any problems I have had with the tents I have owned BD has fixed promptly for free. With that said both models seemed comparable.
I know at least two other threads exist that cover the same topic... consider searching the gear critic forum.