This product is terrific. I have bought 2 of these carts (along with the optional bags) during the last 6 months. First I bought the cart and bag for some friends of mine. He is 71 years old and they live in a 3rd floor apartment. (no elevator) I worried about them having to male 2-3 trips to haul their groceries in. Well they love it. Made it possible for them to get all their groceries up the 3 flights of stairs with only one trip. They even sent me a picture of him using it. So I bought one myself. I'm 69. I don't have 3 flights of stairs only 1 flight of stairs in my house, but there are times I would like to bring a heavy item like a lamp or piles of laundry up or down the stairs and this makes it so easy. I also have a detached garage, so I leave it in the garage when I go shopping and then load it with all my groceries, so I only have to make one trip. If its raining or snowing, no problem, the cart goes with no problem. At first I thought it a little pricey, but after using it I think its worth every penny.

Had it for a couple months now. 73yoF, here, so I need help getting groceries up the 19 steps to my 2nd floor apt. I think this cart is going to be invaluable. Hauling stuff up here has been the only drawback to the many benefits of upper floor living.

Weighed it. 11.4 lbs with the bag.

Pros:
-Definitely makes getting up the stairs easier.
-Carries at least 3 times as much as I can normally handle
-Optional, well designed bag available
-Bag is excellent, if it's attached properly with its velcro straps
-Sits on each step, so user can rest
-Wheels turn easily
-Wheels climb just fine on my open steps. Opening is 5".
-Didn't need a half hour break before I put the groceries away, which used to be the case making 5 or 8 trips up those steps carrying heavy loads.
-Yellow. My favorite color.

Cons:
-Hard to make sure the wheels are locked open.
-Major design flaw is that, when the car is upright and resting on the front brace, even a slight nudge forward can unlock the wheels and start them folding. I dropped a star off for this. Even sitting on an incline could cause a collapse. Wish I knew of a way to brace the wheels open.
-Accidentally kicking one of the protruding wheels can nudge it just enough to start it folding.
-Lot of dead weight at 11.4 pounds. I'd pay more for something as strong or stronger made from lighter materials.
-Lot of plastic. Not sure how long it will last.

Hope Trifold is reading these comments. Others have wished for lighter, stronger, even faced with higher cost.

Works well and as advertised. The bag is very useful.

The reason for 4 instead of 5 stars:

1. The cart is a little heavy for me. I have a chronic illness that gets me tired very quickly, but live on the third floor of a walk-up, so this is important. However, it does seem sturdy, and most of the weight appears to be in the wheels, so I guess that is the trade-off.
2. The "shelf" part of the cart has SIDES, so you are limited in the width of the item that you can put on the cart. This is the most limiting part, and it can be very frustrating. Things that are wide and skinny can be particularly annoying to put onto it, because you will have to position it with the wide length perpendicular to the cart, making the center of gravity of the whole thing less than ideal. If I could improve one thing on the cart, this would be it.
3. The bag needs more "pouch"-style pockets, and bigger ones, at that. There are just two pockets - one is just a flap of fabric seen on the front, so it's only good for very thing items, and the other is a small pouch pocket with a closure flap that would be very handy of it weren't too small to hold anything more than a couple rolls of quarters. They are also both on the outside. Considering that an obvious use for the bag is for laundry, this is a huge oversight. I just use a the smallest possible bag of detergent "pods", a similarly small box of dryer sheets, and, of course, the quarters, and there is not enough room in the pockets for these - I have to meter out exactly how many pods and sheets I need and put them into plastic baggies. Very annoying.

That being said, my review is overall very positive. The thing appears to be very sturdy and climbs very well. I would be lost without it, and get lots of envious comments about it. The bag is very sturdy, also, and attaches well to the cart at three places. You will need bungee cords - the ones that AMAZON recommends work well with this cart. It folds nicely and is surprisingly compact.

Best purchase all year!! My garage is as far away from my kitchen as it could be and still be attached. There is one step up from the garage. I used to have to make several trips transporting groceries from my car to the kitchen. With this wonderful "UpCart" and the large tote bag that came with it, I can load all my groceries in the bag and easily maneuver it up the step and all the way to the kitchen. The rubber on the wheels does not mar floors, even when turning sharply. I also use it when moving anything heavy upstairs or downstairs from my second floor bedrooms and storeroom. It goes up the carpeted steps easily. The handle extends longer than those on most similar carts, which is crucial when you're pulling it up a flight of stairs. In the spring I used it to haul heavy potted plants and bags of mulch to my patio. I'm a senior citizen and these tasks would often leave me with back pain or I would do the job over several days to minimize the strain on my back. This year it was easy with this cart. It folds easily for storage, but I just leave it open and parked in the garage, ready for the next load.

I was so impressed with the videos of this cart that I knew I wanted one. It folds well, is a champ on stairs, and is easy to manage. There is one design flaw that sort of changes my plans for its use. The hinges are in the way if one wants to haul plastic storage boxes or larger boxes. Round things fit well, and smaller or things put in the bag would work. I wanted to use it like a dolly, it is limited. The platform and space between the hinges is only 16 1/2 inches. I wanted it to move my big heavy sewing machine that is over 20 inches wide.