Older lens, as in, just FD lenses or...?
I myself swear by old analog glass. I love it! It's cheap, great build quality, the IQ for the price is amazing, super smooth manual focus ring and it's really easy to come
I love fiddling around with manually exposing and getting everything in focus. I learned a lot from my analog glass.
The IQ tends to be on par with some of the best glass around nowadays.
I'd say the only downside to analog glass is that the apertures don't tend to be as big as glass from today (this is especially for longer lenses).
Personally I haven't got any FD lenses (too much hassle), but am a big fan of easily convertible glass like M42/OM/K/F mount glass. Take a loot at SMC (Super-Multi-Coated) Takumar, Olympus OM Zuiko, Carl Zeiss and Nikon Nikkor glass. Maybe it's an idea to take a look at the thread where people showcase their pictures taken with MF glass. You'll see a lot of lenses used by a great many people.
I'm not saying all analog glass beats glass from today (although it probably does in build quality), but there's a lot of good lenses out there!