EF 135 F2.0 L Stacked TC's

Hi All

I'm new to this forum so go easy on me... LOL

Just wondering, do any of you stack TC with a 135 F2.0 L Lens? The reason for asking is i sometimes take pictures that require a bit more reach than i already have. I use a 135L and sometime use it with a 1.4X TC and wondered what the results would be like with say a 2X TC and maybe a 1.4+2.0 TC.

Looking at the ISO 12233 Chart's on the-digital-picture.com the 135L +2x TC giving a 270mm f4 look to give better results than a lot of 200mm Zooms which then have a 1.4x and a 2.0x TC added to them.

eg.
http://www.the-digital-picture.com …omp=0&FLIComp=5​&APIComp=1

Anyone got any samples of a 135L @ 378mm (135+1.4+2.0)

Thanks for reading.