I bought this set some time ago to be able to power my 8285-set. At least I thought it could be done with this one, but alas. That said, I tried to make a MOC of this 8285, but now with the motor and the lights inside. This really went super-easy since it is a medium motor that does not take in too much space. Most models Lego creates, have an uneven number of studs as width, so this will fit in in some way.
The content of the set is a bit meager but then again, it is an addition to your normal sets. MOst PF-able sets do this based on this add-on set and does not include too much extra parts.

Pros

• Price
  Usability
  

Cons

• Not a usable set on itself

Conclusion: when you do not own any sets with Power Functions, this is value for money, but keep in mind not all sets have an option to be PF-ed from within the building manual. You need to figure this out yourself. On the other hand: that's what Lego is all about.

I recently picked up the red metro train. This set was great add on to the train to indicate if the power is on or not by integrating the lights into the metro, as i have it set to turn on when the power switch is then piggybacked the ir receiver. it was hard to get the wires stuffed into the nose of the train, but looks awesome when its running. I also changed the lens colours on the front of the train for added effect.

I first got this set two years ago for Christmas and was really excited to have it for a couple of reasons. First, this was my first motor kit I received and it included some new attachments I haven't had before. Secondly, It was going to help me in some of my own creations I made. Now I must say I don't own the 8297 or 8294 to put this kit into it, but I mainly wanted this set to help me start getting familiar with the whole (PF) power functions stuff. The motor is cool and so is the LED lights. I was surprised to how bright the lights were. There were a few other small elements included also like: universal joints and gears. Sadly though, this kit didn't come with all the "extra" stuff one would need to fully motorize a creation of there own. To name a few of the missing parts I think that are not included are: An IR receiver, an XL motor, and remote. Those extra pieces would definitely have helped this set a lot. Although it might have possibly raised the price of the kit, I still would have gotten it for just that. To conclude, this set is still available to purchase and is a good kit just to have the PF elements ready to use at your disposal. Despite the missing remote and stuff, this set is a good follow up kit that includes some pretty cool parts to help start you on motorizing your lego stuff. 

I bought this for my son, and we have motorised everything! With the brilliant switch you can build machines which change direction when the reach an obstacle which is cool.

The motor is reasonably powerful, the lights add fun, and the batteries last for ages. Adding a slip cog (clutch) to the kit is a great idea.

Now for the downsides:

1) The leads are a bit delicate, the motor lead already had an internal fault so I had to shorten it (this is NOT easy!!)

2) The motor could do with lego bumps on the top to give more mounting options

3) The battery box is HUGE so it's hard to integrate into smaller sets. It takes 6xAA batteries.

4) The battery box has no lego bumps for mounting and the mounting points on the ends have an inconvenient 3M spacing with a 1/2M offset to the edge of the box. Very awkward and always tricky to mount.

5) The centre OFF position of the battery box switch can be tricky to find when you want to switch off in a hurry

But I'm being really fussy here, it's a good set. It just could be slightly better.

At first this set looks kind of disappointing because of the small number of parts for rather a big price.
Compared to 8287, which included plenty of useful gearing, axles, transmission parts, etc., we get only one clutch gear, one 24-gear, and surprisingly three 5-long axles, three 8-gear (not one) and three (again not one) new 3-long u-joints.
Also the M-sized PF motor is not so powerful as the motor in 8287.
But as a perfect addition we get lights and a pole-reverser, which is the first time in years in a Technic set.
Lights are okay, not so bright, but so they will not eat all the power in a small time.
Pole-reverser has three positions (including neutral) and additional direction switch. Difference between positions is approximately 15 degrees.

This set is perfect and must have addition for this year sets (8294, 8295). You get friendly operation of their functionality, and not to rotate gear manually which is annoying. Lights also give a nice touch.

Personally I wish that the set included additional PF connection wire, because I have had several times where the length of cables attached to PF motors was not enough. It would be very useful, at least here in Russia where we can't order parts from S@H. Okay, asking for linear actuator (we also can't buy marvelous 8294 set here :( It is too much, I know. :)