Macro On The Cheap - Zeikos Extension Tube Set Review

So I went on a little accessory spending spree last week and ended up buying a few things to outfit and expand my D7000 a little. Now the best accessory to any camera is a new lens and I did that already with the addition of  a 50mm f/1.8 I'll talk more about that later, but today I wanted to share with you the cheapest way to get into Macro and still get some good results all without having to shell out mega $$ for a dedicated Macro lens.
Like many photographers I spend way too much time trying to learn everything possible about this crazy addictive hobby/obsession and at some point I stumbled upon the term "extension tubes", (I've used these in my astrophotography although they're configured a bit differently)  these are basically rings you add between the camera and the lens to adjust the focal distance of a lens to make it focus at much closer distances. Most normal range lenses focus around 1-2 feet, and even farther out for the larger tele-zooms.  Using an extension tube or set of tubes you can shrink this down to mere inches. Here's the best part - they work on most lenses, and they're cheap!
While cruising through Amazon on this buying spree I was exposed to the "you might like this" scrolling bar and noticed a set of Kenko Extension tubes they looked great and cost $170, I did a little research into the brand and found good reviews but I also found an alternative set of Macro extension tubes from Zeikos that only cost $79!
Add to cart!! They arrived a few days ago and I've been taking pictures of  my wife's wilting Mothers Day flowers, and I have to say I am really impressed by how close I can focus with these tubes on. The set is comprised of three tubes (rings) of different lengths 12mm, 20mm, and 36mm that can be used alone or in any combination. The great thing about these are that they contain the electrical contacts necessary to enable the use of autofocus and metering. My 50mm f/1.8 will even autofocus through the tubes which  requires the cameras autofoucs motor to work, don't ask me how it works through three extension tubes, that's voodoo magic to me but it works.
Here are a few shots showing the flowers using various tube combinations and some wide scene shots to give you some perspective.

Here you see the three extension tubes next to my D7000

All three tubes and my 50mm f/1.8 as I shoot the Daisy

Here's the result of all 3 tubes on a 50mm @ f/22

How about some HDR shots?!

A purple Daisy backlit with the 12mm tube on a 50mm @f/5.6

Backlit petals of a Yellow/Green daisy 20mm extension tube with a 50mm @f22

The same Daisy from the front

Here's a regular shot of the smallest flower with all 3 tubes shot @f/22

The smallest flower in the arrangement, shot with all 3 tubes @ f/22

The set up for the small flower shot with all 3 tubes

As you can see you can get very close using these extension tubes. They're made of plastic but have metal components including the mounting rings, one thing to note is that you must mount the tubes onto the camera before mounting the lens onto the tubes (per instructions). They started out pretty stiff but have loosened up just a little so it doesn't feel like I'm going to squeeze my lens into an oval getting it on, they mount onto the camera and each other very easily, only the lens takes some effort.
I look forward to using these often, especially with my 18-200mm which I just haven't had the time to try out yet.
Happy CHEAP Macro shooting!