I have no dog in this fight, but I did do my homework on all of the available kits on the market for our cars.
Don't let the hype fool you. One thing is an absolute truth, the only "functional" part of these kits is the GM Sensor that they all use, even the "cheap" kit.
For years the "big" names charged an excessive amount because no one came out with a less expensive alternative. The SMG kit uses high quality parts, from the precision billet aluminum adapter with double o-ring seals, to OEM style connectors and top quality wiring harnesses.
Source? I personally have seen all of them on cars in my area, have read all of the websites and fourms asking these very questions (I have time on my hands to read, so I do) ultimately I bought this SMG kit (see some pics below), and have zero complaints. Its fantastically built, the materials are great, the harness is well protected and attractive (for a wire harness anyway) its fully sleaved with a bice braided loom, connections are nice and solid, no funky athletic tape or similar. very nice kit.
-is the wiring any more complicated?
I don't think so. sure the dsx kit piggy backs off a coil for power so you have to plug in their jumper harness, but you still need to run the signal wire to the PCM
(just like ALL Kits), the SMG kits have a simple ground wire that connects to a factory bolt right next to the sensor, and a fuse adapter you simply route to the fuse box and plug in, which just so happens to be the same general location the pcm wire has to be routed anyway so its not any extra work...
Is the dedicated power and ground wires better?...I personally prefer this design because it allows you to have a dedicated fused circuit for the sensor (just like OEM sensors have) vs piggy backing off another important component like a coil for power adding load to a circuit designed only for it...
-the other question, does it look any worse?
I also don't think so, just glance and you'd be hard pressed to see a difference once installed. Its the same sensor mounted in the same place. The addition of the new hose from a few of the other guys, is unnecessary and looks just like oem so there is no visible benefit. if anything the nice finish on the SMG billet adapter is very nice, but blends in and looks OEM, one exception to this is the RPM kit
https://www.rpm-motorsports.com/stor...ersion-kit-e85 YIKES!!!! Worm gear clamps and plastic barbed fittings for fuel injection??? NOPE
So ultimately the decision is yours, buy what you feel in your gut to be the best fit.
You are gonna hear the fan boys from each brand pipe in and recommend the kit they bought because it validates their decision, that doesn't mean they have any direct knowledge with the other kits. You'll also hear from vendors that pay to be here that their kit is best, be wary of any that disparage their competition. Lastly, read up on the customer service stories of each. I've seen numerous on this site and many on the fb pages too. I personally buy from vendors that do right by their customers, even more so after the sale has been completed.
Good luck, I hope you find a product that fits your needs and you are happy with in the end.
edit: forgot to add, no funky tools were needed to install either, the little aluminum caps can be snugged up with a wrench, but who doesn't have that?, a pic, needle nose and a side cutter to trim my zip ties to secure my routed wire... I am missing a few fingers and still managed to get this installed in under 30 minutes, including time to down a few beers :cheers: