I bought one of this, ten days ago. I 've already used it five times. According to my short-lived experience, I will lay out some usefull imho information on manual treadmills in general(mostly answers to questions I had myself, before buying one of these), and then my thoughts on the quality of this particular product.
1. This is a non-motorized(magnetic) treadmill. This practically means, that you 'll need to keep your hands on the handles at all times(which might be an issue for really tall people. I am a little over 6ft and I feel like, it would have been better, if the handles were build a little bit higher. This depends on the model of the treadmill I guess). There is no way to control the speed at which you are running elsewise, and unless you do that, you 'll end up surely with your face on the floor(it accelerates non-stop, if you don't keep grabing the handles).
2. You can walk/run on it, as fast/long as you want(According to the digital display, I 've managed to hit more than 22km/h, while testing it). Bear in mind, that it has a native, non-changeable inclination of 8%, and you'll be the one, moving the belt(my point is, that it is way more difficult, than just jogging ouside. It helps a lot if you apply some pure silicone grease/spray under the belt from time to time). To put things into perspective, I usually jog at 12-13km/h for a whole hour outside(and I am able to do 20sec sprints every few minutes), or run 4x5km laps with short breaks in between, in 2 hours time. At the same speed on this treadmill, I am out of breath after just 10 minutes, so I usually end up doing 4-5x2km "laps". In my experience, it's at least twice as hard, as normal jogging(and that's only after your legs you get used to it).
3. I've read a lot on the internet, about joint friction caused by manual treadmills(attributed to the fact, that you move and stop the belt manually). Again imo I don't think that that's right at all. I feel like it's a lot easier on my joints and feet overall, than running on the street, as I usually do.
* So if you are on a budget, and you want to walk/jog while watching your favorite tv program, or you don't want to walk/jog outside, because of the weather etc, then a manual treadmill is a really good idea. Although the fact that running on it is so difficult, means that unless you are in a pretty fit shape or you intend to use it primarily for walking, it won't be as useful to you, as a motorized one. Don't forget, that cardio excersises make more sense when they last long, as opposed to being fast and intense.
So is the V-Fit MTT1 any good?
1. I had no problem whatsoever of assembling it. I took me 10' tops. Everything that you'll need is included, except batteries for the digital display(although a small silicone grease tube, would be a nice addition too). There was an issue however, with the connections of the digital display. It has 2 wires, that could be connected either way(In fact I tried both ways, but nothing seem to change at all).
2. I didn't experience any problems with the belt, but I ended up messing around with it, just to see what the whole deal is about. Indeed it's quite easy fixing the problem, if it happens to you(it happens on all treadmills, even the very expensive motorized ones).
3. The digital display works properly, but there are some issues with it. The speedometer works in real time. This is not very useful as you might understand, because your speed will change infinite times every second(it's not constant, as you are the one setting it by walking/running), so if this takes five samples/second and shows it on the display, it will only confuse you. It would be much more useful, had it calculated/shown your mean speed every 1-2sec or so. Furthermore, the heart rate monitor is definately faulty. It keeps showing ~70bpm everytime I put my palms on the handles, no matter what I do, and it rises slowly up to 110-120bpm after a minute or two. The side effect of this of course is, that it miscalculates the amount of calories you end up burning. Even if it didn't have this problem, it would still not be accurate enough. It would at least need to know my gender/age/weight, to calculate the calories burnt properly. So even if the heart rate monitor specifically on my product is faulty, the digital display in general has a lot of issues, that prevent it from being really useful.
4. It is noisy, but if you turn up the volume on the TV, or if you use earphones, you'll have no problem with it.
5. Last but not least, its quality. There is none to be found ;p. It started squeeking, the second I got on it. I weigh 77kg(~170lb), so that shouldn't have been a problem(it's supposedly made for people up to 100kg). I don't think it's going to make it for more than a few months. I hope it breaks down, after winter is over, so that I can start jogging outside once more. When it happens(or if it makes it for a whole year, although i seriously doubt it), I will edit this review, to let you know.
Manual treadmills: a family of products with certain limitations for people on a budget.
V-Fit MTT1: a cheaply made product, with some issues of its own(mostly refering to the digital display).
Should you buy it?
If you are on a tight budget, not very heavy/tall, and primaliry interested in walking/power walking inside your house(just using it for walking, I assume will help with the lifespan of the product), for 93/79£ you can't go wrong with it.
UPDATE: After 40-50 uses it's still in one piece(I usually power walk for 10', then run for 40', then power walk another 10' on it). It's screws need a little tightening every now and then and the digital display resets on its own sometimes, but other than that it has served me well for the past months. It has earned the fourth star imo.