I've run Serpent, Mugen and now Kyosho... just my experiences here from an average Joe racer......
Jaco- I'll be the first here who is spending his own money to say that I will only purchase Jaco's
I find them an extremely attractive tire in all aspects. Strong new rims, good wear, good traction and as chunk resistant of a tire as they get. You can see they glue these bad boys real good.... the glue is visible between the rim and tire. At last years GLC I was pitted right across from Paulo and showed him that my rims were cracking around the rear axle pins. He took a set of my used rims and an axle pin to take back with him so the fit could be corrected. They are now perfectly fitting rims! Jack was kind enough to give me durometer info so I could purchase the correct style for my personal use. Best price/performance value
in my book. Look in the trash can at any big event.... they are full of Jaco boxes- that tells you something.
ATS- I've run these a few times in a pinch and had good results. Prices similar to Jaco's.
GRP- (GRP, FAST, Ennetti, etc..)- good wear, rims and traction. I've noticed GRP has amazingly accurate shore ratings on thier tires. However, way too expensive for the average racer..... crossed off my list.
Twister- I have not had great luck with these on my 1/8th scale in the past, but they were great in my sedan. The 1/8th Mugen/Kyosho style rear rims were way too sloppy and caused them to wear very quickly around the rear axle. It was impossible to set my car up using Twisters. I hear they have changed the rim design and they fit Mugen and Kyosho better on the axle now. I would run them again if the rims were truly fixed and I had a cause to switch from Jaco's. Omar is great to deal with..... just not during hurricane season..... LOL
I have personally not tried the Kyosho, Zac, GQ, Kawahara, or Microsystem tires, but one of my friends had a fluke with the Kyosho's..... a few weeks ago his rear tire sepaparated from the rim. You could see there was no glue where it came apart. This could happen to anyone in mass production I guess. I will note he won the point race at our track last year on Jaco tires and is the fastest local racer at our track on nearly any tire he runs.
I run a Kyosho Evolva currently, but the cost of the red box tires prevents me from even wanting to try them. Kawahara and Zac are quite expensive for my wallet as well. I have not priced GQ's, and really to be honest, didn't even hear of Microsysytems till this post
A lot of big boy's run the Jaco's and that didn't even play into my decision. I'm an average Joe racer who likes good stuff and a good price. Jaco was an easy choice for me.