I'm torn on how to rate this product. From a performance standpoint, I give it five stars so far considering I have only had it in place for a week or two. The lights are very bright and do a good job of lighting up the space (whites and colors look great to me). I used one of these strips above a bay window on a vaulted ceiling. The lights stuck well to the ceiling (so far at least) and are bright enough for me to not have to worry about going to all of the trouble and expense to retrofit canned lights into the same space. I pared these lights with one of the new Philips wall dimmer switches, which has worked very well.
The lights are definitely a five star product if you are installing the lights in a straight line. Whether it's across the top of kitchen cabinets, or a vaulted ceiling, as long as you do not have to worry about any angles, I think you will be very happy with the lights.
The lights are not very pleasing to look at if they are visible to the eye. I had intended on putting these in a few more spots such as under the trim below my windows, and in other similar areas. However, my wife did not like this and demanded that I remove the lights from any location where they were not completely hidden. In her defense, I did not really like seeing the visible lights either and we have decided to use them in only locations where they are completely concealed. I don't remove any stars for this since it is as intended I believe. The lights are thin, but you may be surprised by how visible the actual light strand is if you are trying to put these in non traditional areas.
The power block that goes into the wall outlet is big, so that may be an issue for you. While it was not great, I was able to burry it behind furniture, so it can't be seen. The cord from the wall outlet to the lights is about six feet, so you may have to worry about hiding the extra cable depending on where you are installing the lights (there is a second smaller brick that the lightstrip plugs into that you will need to deal with as well).
From an installation standpoint, I would give this a 3 1/2 star rating. While these strips are very bendable up and down, they do not bend well at all when installing on horizontal angles. You can forget about using these on any 90 degree angles, and 45 degree angles are not much better. You will not be able to easily install the strip flat at the angle if you have to bend the strip to the right, or the left since Philips does not offer any kind of adapter for this (as long as the strip stays straight, you are good). You will need to curve or loop the strip at the angle, which may throw off the light pattern a little in that spot. You will also need to make sure you have plenty of room to hide the curve/loop you need to make to get around the angle, or it will be visible. You will also probably need additional adhesive of some sort to strengthen the area around the loop on both sides of the angle.
The few negatives aside, I think this is a great product if it matches what your intended use is. I held off buying the first generation because they were not bright enough, and not long enough. Hopefully Philips will incorporate adapters for future products that allow you to cut and install the strips easily around angles. Other brands already have this, so hopefully Philips will do the same. I also look forward to Philips producing a product like this that can be used outdoors. If these were rated for the outdoors, and could be installed at 90 degree angles, I would love to put these all around my deck out back (among other locations).
I have also used the new expansion strips. They connect easily and have the same positives and limitations as mentioned above.