Fireplaces, Heating Stoves, Flues and Chimneys - (oil burner) Chimney flue liner or Supaflu ?

We installed a new higher-efficiency furnace in December. The house and chimney are old, and there is currently no chimney liner. Now the chimney doesn't draw properly and there is condensation causing leaching and staining on the inside of the chimney in the attic. We have looked into having a new liner or (cast-in-place) Supaflu. The liner would cost much less than the (cast-in-place) Supaflu, which is a molded flue (poured around an inflated tube, which is extracted later). We like the idea of the increased structural support of the Supaflu. We were told by the Supaflu guy that with the liner, loose stone could fall and cause problems with the liner, and that it would be too tight to put insulation around the liner. On the other hand, should we be concerned that the molded flue will crack when the house shifts? Does anyone have any experience with Supaflu?

Supaflu sounds like a great product. Make sure you do repairs to chimney in order to address the moisture issues. Make sure chimney is structurally sound in order to assure that no stones will fall. Supaflu is supposed to provide greater structural support.