Has anyone ever tried these stands before? I was thinking about getting one for my 38 gallon.

I have one of the Aquatic fundamentals stands under my 40b. The build is good, and it seems sturdy. There are a couple areas that had exposed wood on the inside, I filled those holes with epoxy to make sure it did not produce any problems later on with water getting in them.

Does it feel like cheap particle board wood at all?

I have 4 of this design in different sizes and love them. Found them to be very sturdy and I don't think they feel cheap at all. They were also easy to put together.

http://www.petco.com/product/101394/...tandsFurniture

I looked them up and listed under "Fundamentals" are several types including what is commonly called "Wrought Iron" or metal frame type.
If you seek a cabinet type, I can't recommend any except the ones that Glass Cages make.
http://www.glasscages.com/?sAction=ViewCat&lCatID=7
But if you are looking for the metal frame type, I have two of the Brooklyn type
and love them. I find they are the most sturdy stands that I have ever tried.
But I have never had a cabinet type before. And I also put wood under the ends of the legs because I think those little round pads would eventually sink into the floor.
http://www.petco.com/product/119923/...ank-Stand.aspx

Yeah Petco doesn't make a metal stand that will fit my 38 sized tank, 36x12, exactly. or else I'd definitely get one.

I'm really kind of peeved that they had the Aquatic Fundamentals stand on sale for 69.99 the past few days or so, and now it's back to 99.99 all of a sudden.

I should just save my self all the trouble and go with the Aqueon 45 setup at petsmart, which for 200 bucks, 40 dollars more than the 38 tank by itself without the stand, comes with a great stand already assembled. But I really, really don't want to deal with a tank that's 24 inches tall. I don't want to have to have a tank to have so many background plants to use up that space.

I Bought an aquatic fundamentals stand a few months ago for my 55 gallon acrylic tank. I've been happy with it. Seems sturdy and not too much like particle board. For the price I think it's a good value (I think it was $105 at petco?).
The only thing to watch is that you have to be careful with water sitting on on the wood too long, as it makes the paint bubble slightly. Not a big deal as I usual don't let water sit on my stand, but I know others have given that feedback.