Should I upgrade?

I have an older (21 yrs old) Denon direct drive DP-33F fully auto (I only use the auto lift function). I was going to upgrade to one of the Pro-Ject model tables (RM-5 or Xperience). But lately I've been hearing that maybe I should keep my old table and get a better cartridge and invest in a phono amp. I'm at a lost, any help would be greatly appreciated.
Thanks