I live in the US and I am with PARC, that is my only complaint with them really, I have to buy supplemental insurance for my family because they are covered anywhere in the world except the US
outside of that fact, I'm pretty satisfied with their service thus far.
Taxes:
There really is no tax advantage by going with CREW vs. PARC if you are in the US, the only difference is that PARC will not make social security contributions and CREW will since they are a US based company, with PARC you will have to file as self employed every quarter but with this file scheme you are still able to contribute to the SS and will have the same tax advantages (per diem deductions) as you would with any company while working abroad.
Per diem:
We are spending around 8 to 10 nights in Narita and the per diem doesn't cover it by far, specially now that the ¥ is so strong against the $
guys are sharing apartments and that does help with the cost, it also depends on what kind of life style you will have while at work, there are the "slam clack" types that all you hear is the slam of the door and the clack of the lock, followed by the sound of the McDonnalds paper bag, this guys of course spend a lot less, but if you are like the majority of us that enjoy a good meal and a nice glass of wine here and there, you will spend more than your allowance for sure, the dollar is weak right now against pretty much all the currencies of the places we overnight at.