I'll start by saying that while I ended up returning everything I ordered, it wasn't necessarily a "bad" experience, just an extremely frustrating one. Customer service was very good and willing to do anything.
Background: I had (still have) zero knowledge of clothing, fitment, etc. I had started a new job where a jacket everyday is not out of place. I had at that time one JOS suit in my closet that I had bought 8 years ago, and really only one suitable dress shirt. So, I did some searching, discovered M2M and Indochino. I'm a pretty standard build, 5'11" and 175. The one issue is I have a fat neck, 16.5 - 17 so OTR shirts are usually really baggy on me.
My wife took my initial body measurements. It was somewhat confusing and we debated half inches back and forth for an hour. Eventually we settled on some numbers. I ordered, on Jan 31, 2016:
Charcoal 3-piece suit.
No crazy style details, all pretty standard. Round 1 arrived 3/1. In the meantime I had discovered a local tailor who is fantastic, and I had taken a few OTR stuff to him to get slimmed. I brought everything to him (full disclosure, he is also a J. Hilburn rep).
He said fabric and construction were good.
Shirts were really tight, pretty much everywhere, and they don't give a lot of extra fabric in the seams to do much about it.
Pants were a bit big in the rise/thighs/waist
Jacket was tight in the shoulders and giant in the waist. So I had it all remade. Instead of remaking all 5, they'd just remake one until the fit was right.
Round 2 (3/25):
Jacket - instead of adding 1", they subtracted it.
Pants - Fit was better in the seat/rise/thigh but for some reason they cut the legs really strangely, even though I hadn't asked for any alterations here. Essentially the knee was smaller than the opening, creating a subtle bell bottom look.
Shirt - Still pretty tight in the armpits, elbow. As soon as I raised my arms the shirt would start cutting into my biceps.
All went back (except the vest).
Round 3 (5/3):
Jacket - at this point I was getting knowledgeable about fit/measurements, and so in the last round of remakes I had specifically asked for 19.5" shoulder. The 3rd jacket was slightly under 19, and this was enough to cause dimpling.
Pants - Fit fine.
Shirt - No change. Apparently the rep forgot to submit the changes....
Jacket and shirt went back....
Round 4.5 (5/31):
New shirt came before the jacket. There was a bit more room in the biceps and armpits, however it just felt tight. Quick measurements showed the chest was tighter by ~0.5", even though I had requested an increase. Closer inspection showed the front and back chest pieces were uneven - that is, the back was smaller than the front. The difference was about 0.75". This caused really severe tightness across the shoulder blades when I raised my arms.
At this point it's 4 months since I've placed my initial order. True fitment issues are one thing but 5 of the returns were caused by either systemic issues or just bad manufacturing (subtracting 1" in jacket shoulders instead of adding; strange, bell bottom cut in the trouser legs, ordering a shirt remake without making any changes, jacket shoulder again not to where I had requested, poor construction in the last shirt making the back piece tighter than the front). So, I sent back the whole lot permanently.
Looking back, I wonder if pleats (indochino's default is no pleats, and you can't even add them unless you talk to a rep) would help alleviate the tightness in the arms. Their default cut is very slim - I think eventually I would have walked myself toward a correct fit by slowly increasing measurements until it fit but with the QC issues I felt it would have taken a long time.