Should I watch the old Doctor Who?

If you like the basic premise of the Doctor and his adventures, sure, why not?

Just be aware that the older series was run on a shoestring budget long before digital effects were available, let alone, relatively cheap like today. Quite honestly I'm surprised the older series looked half as good as it did. They certainly didn't have much - but they certainly made the best of it. It really does have that feeling of a bunch of kids playing make-believe where the guy in the goofy monster suit isn't nearly as scary as the monster you imagine in your head.

The original Cybermen are quite different than the stomppity-stomppity ones in the new series.

You'll also see how the Daleks were created, and how the Doctor had a chance to stop it...but didn't, and his reason will surprise you. (although I think the "new" Doctor wouldn't have hesitated to wipe out the Daleks before they began.)

Overall the older Doctor series are much more like a Sherlock Holmes story with the ever changing cast of companions acting as his Dr. Watson.

Yes, it's really fascinating to look at the old Doctors and their characteristics and not just stick to these recent three. It's good to see how it's changed and the old special effects are adorable. Also I find the episodes with Daleks and Cybermen so much more entertaining and thrilling then these recent episodes with them in. I still love this new Who but old Who is greatly loved and you'll see why when you watch it.

Also come fantastic episodes with Sarah Jane with the Doctor in his third and forth carnations.

Hope this helped, just my opinion!

yes- to understand it and monsters like the Dalek & Cybermen history

Just remember the Original series was a Children's show- it wasmainlly aired on Sat afternoons in the uk

and so had a Small Budget and it was made before modern FX-

The rebooted series is a primetime show with a primetime budget & modern FX

One thing I miss in the rebooted series is the Multi part stories- they took time to tell a complete story

Absolutely!