Does it make sense to buy SACD of old recordings?

HI, I am very new to the world of SACD. In fact I just purchased an SACD player (for reasons other than SACD) and I do not yet have any SACD. So I was wondering if SACD makes a difference for old jazz recordings like Ella Fitzgerald, Sarah Vaughn, Wes Montgomery, etc? My initial thought is SACD will not make a difference since these old recordings are of such poor quality anyway that SACD would just reveal more of the bad recordings. Along the same lines, is SACD really most beneficial for modern recordings?
I agree with Metralla. I have about 100 SACDs. I believe they are generally an improvement over redbook, but that is variable. I like "Ella and Louis" on Verve, but also like Sam Cook, Diana Krall, Patricia Barber, Norah Jones, Ray Charles duet album, Nat King Cole, Natalie Cole. I also like the ones mentioned above including Ray Brown, Bill Evans, Miles, and Brubeck. And there is alot of well recorded classical music reissued on SACD... some much better than the old, in my opinion. has much of what's available, but you can't preview.
I suspect it depends on what source was available at the time of recording. If the performance was capured in much higher fidelity than the distribution medium, e.g. standard mass produced CD or vinyl -- send hate mail elsewhere, then DSD remastering seems to be of great benefit.

Definately look for reviews on the sound quality. I have Dave Broubek's Time Out and it sounds amazing.

But I've been burned by buying older recordings that were just tranferred over to SACD and sound terrible.
To be honest is the best place. The next option is hi end magazines, reviews SACDs/CDs and mentions sound quality. Or look for what you want on SACD and then start a thread asking for other owners if it's worth it sound quality wize.