Both camp has their fair share of macro fans. I do have the mpe65. Here's a pic taken with it [link]
I love this lens but it's not very practical to use because the insects here are very active. Due to the close working distance, before i can focus, the insect will flee or the moments will be gone. Now i just use my Tamron 90mm and if i need to get closer, i'll add a rayonx 250 closeup filter(+10).