I have the Cuisinart 3.5 quart programmable. It has a High and Low setting PLUS a Simmer setting which is the "old-school low". It also has a Warm setting which is the bottom... only used to maintain temp after cooking. It has a timer that you can set and when it finishes cooking, automatically switches to Warm.
You don't have to worry about overcooking with this so much. Even if you cook on High and you leave home - as long as you set a timer, after the cooking time ends the machine will automatically switch to Warm in order to maintain. So during this time, it's not like all the liquids will stay hot and evaporate away over 12 hours or so.
Basically your specs are exactly what I wanted and I went with this one after reading the reviews. Many people on Amazon like this product and so do I. I even bought one for my mother. I have had no problems with it and it just works.
Also note - if this is for 1-2 people - 3.5 quarts is PLENTY huge. I can't even imagine having a 6 quart slow cooker. Even for a family of 3-4 you can definitely use a 3.5 quart to make one dish and then have others that will compliment and add extra food on the table.
This is the 4qt version of the crock pot I've used for several years. I love my 6qt model, got a pot roast going now in fact. Will set for 4 or 6 hours on high, 8 or 10 hours on low. Switches to warm automatically. Cooked all sorts of stuff in mine and never had any issues. Not Prime (probably why there aren't tons of reviews) but still ships for free.
This one gives you more flexibility with setting a specific time. I can't speak to it myself because I never used a Cuisinart model, but it's got good reviews and is a Prime item.
Scroll down a little on the product pages, Amazon should have a list/chart comparing similar items. You might find one you like by checking those lists as well.
This is very you dependent. How many are you cooking for, what meals do you envision making what size meals are going to be the norm?
I have 5 slow cookers. From one that is for dip, just an on/off to two 6qt, one programmable the the other a turn nob. And believe it or not I use all of them from time to time.
More often than not, this is the one I use. Basically I don't usually cook enough to fill a 6 qt.
It's almost as if the eBay item had a differently-sized crock from the pot it fits in. Or, perhaps, in your country the crock was metric whilst the pot was Imperial, or vice versa.
Don't blow off the Crock-Pot brand; it's fine and popular. But perhaps find a way to get one new, from someplace.
I've studied different brands recently because I wanted a second, smaller one. I bought THIS one for about USD 50 in the USA. But since you want a manual one, there's THIS which is selling for USD 20 in the States. Larger sizes for manual on/off/warm ones are of course more expensive but not radically so.
Smallest you'll find is a 3.5 quart, I have this one and I want to say it is the only 3.5 that is programmable.
Are you cooking for yourself or multiple people?
4 quarts is about the minimum size needed to cook a meal for a family of four. 6 quarts is the most common you'll find in the larger units, and with that you can cook a few days' worth of food for a single person. Also, most slow-cooker recipes are setup for the larger units.
1.5, 2, 3 and 3.5 quart units are also available, but tend not to have the added features, like a timer, automatic temperature switching or removable dish.
EDIT- Crock Pot's Smart-Pot 4 quart digital is a good option.
If you need the extra capacity, go ahead and get a 6 quart version.
If you want something smaller, this 3.5 quart Cuisinart is the only thing I could find under 4 quarts with digital controls.
Cuisinart 3.5 qt (3.3 L) programmable slow cooker
Are you talking about this one? 53.99 - and with prime!