Singlespeed & Fixed Gear - Chain Tensioner Questions

a chain tensioner like this:

http://www.universalcycles.com/images//products/large/16795.jpg (http://www.universalcycles.com/shopping/product_details.php?id=16795)

VS

http://ecx.images-amazon.com/images/I/31nmqJlzD4L._SS500_.jpg (http://www.amazon.com/gp/product/B001CK2IPC/ref=s9_simh_gw_p200_d0_i3?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=center-5&pf_rd_r=1JBG3GQRF79HBN2CVN4S&pf_rd_t=101&pf_rd_p=470939291&pf_rd_i=507846)

VS

http://ecx.images-amazon.com/images/I/31owofco%2B6L._SS500_.jpg (http://www.amazon.com/Single-Speed-Conversion-Kit-Cogs/dp/B0014X6TM0/ref=sr_1_4?ie=UTF8&qid=1295655669&sr=8-4)

I recently purchased the single speed conversion kit (last one) so that I could convert a freehub body to a single speed. The chain tensioner works great and has enough adjustments to really fine tune everything. I have been working on another frame which also needs a tensioner and I'm trying to put it together as cheaply as possible. Has anybody used either of the first two? I like the idea of having a toothed gear, but the Rubber pully seems like it would work just fine.

Anybody using them, any opinions on either of them? I have tried to go without a tensioner, but I just don't have any ratios that work tight enough.

I have used the first and third kinds. I prefer the first type. (1) pushes up on the chain, which means more chain engaging with the cog. They are more robust, and quieter. The 3rd type (one I have is an Axiom), I didn't find the spring strong enough, which made the chain skip sometimes (I had it on a mountain bike). I no longer use the Axiom, as I found a right ratio using a half link.

I have the DMR Bikes version, similar to the first one. At first, I had it set up like a traditional derailleur. I then got a half link and was able to use it in the more ideal fashion pushing up on the chain, as said before, to get more wrap on the rear cog.

No problems at all with the rubber pulley.

Before
http://i256.photobucket.com/albums/hh164/05_GD7/2010-12-08at23-45-07.jpg

After
http://i256.photobucket.com/albums/hh164/05_GD7/2010-12-21at20-22-42.jpg

go to the bmx shop and pick up a half link it is the cheapest way to go they are about $3 or less or you could reuse the Rear derailleur

i've used the first and third personally a few customers run middle option, all of them work fine if set up correctly, some of the better spring loaded tensioners come with a second spring so they can be set up to push up on the chain.

Personally i would recommend the Gussest style one as the best balance of $/Performance, sTs makes a Gusset style tensioner that can be had for less than 30$ the reason this has bot been more popular is the original guesset was quite pricey(who wants to pay 70$ for a tensioner), but thankfully cheap Taiwanese versions have flooded the market.