I have one of these. while not as fancy as some it was super cheap (I got it on sale for $10 at Meijers) and works perfectly for the two of us.

Any brand will burn meals if you leave it in too long. I usually have the low and slow mindset and haven't burned anything (knock on wood) if you leave a chicken breast on high for 12 hours of course it will burn. When it comes to online reviews you have to account a few negatives for people not using the product correctly or not understanding what they were getting. There are also instances of an item having defects that people assume are simply part of the product. It's not often but it definitely happens with any brand of anything. When you see a few hundred reviews that average to 4 stars you know you're doing good. 387 reviews though and it's still a 5 star rating says something to me. I have one like this and like this (so yeah it's 4.5 qts not 3 sorry). the reviews on both are averaged in 5 stars. Read both negative reviews and positive to get more of an idea what the product is like. I've never had an issue with either of my cookers burning especially on low.

*edit. also keep in mind that people are more likely to fill out a review and take the time to comment on items and services that are negative. So while this might be a reasonable ration there have been way more than 300 people that have purchased the product and loved it and just didn't leave a review.