I have three slow cookers. Two were made by HB, a 6-quart "Crock Watcher" from the '80s with removable crock, and a 4-quart "Crock-A-Dial" (Dominion badged) from the '70s with fixed crock, plus an oval shaped Farberware 6-quart with removable crock that's maybe 15 or so years old. All three have the "Auto Shift" feature that starts out on high heat for a relatively short period and then bumps down to low for the remainder of the cooking time. I use that feature a lot.
What I've found is that the Farberware seems to run hotter and cook faster than the older units. We gave Dave's daughter and SIL a slow cooker for a gift several years ago, but I don't remember the make. It had hasps to hold the lid down for traveling, and a snap mechanism to store the included spoon/ladle on the top cover. Per their feedback, it sounded like it behaved similarly to the Farberware. I'm tending to think newer versions run hotter across the board. Perhaps their crocks aren't as thick or are made from different materials than the vintage ones.
So, if you want the low and slow performance of a vintage cooker, you'd be better off finding one of those than buying new, plus, unless you like the rigamarole of getting a new one with a fancy control panel to start cooking, the ease-of-use factor with vintage is superior.