raminmd,
You are absolutely right about the paper. If your clients are ok with it, run Silk or UnCo. I have been able to sell my clients on Silk coating for pretty much everything. It looks good, runs well, mails well.
Straight 1st Class, is by far more expensive, but it's also the safest, as you know. It gets processed and mailed faster, as upposed to possibly taking 2 weeks PRSRT STD. There are advantages of both. I have a pricing grip that I give my clients for postcards and all that is taken into account.
I have had the same situation happen to me with a client wanting to know why there stuff gets beat up ion the mail. It's a touchy subject, b/c the post office will blame the printed peice, the printer will blame the post office for their shoty equipment that hasn't been updated in years. And the poor client, just wants answers. It's a vicious cycle.
I sometimes wonder what it would be if it wasn't gov't regualted also. Like, what wuold it be like if they had some competition (i.e. ups or fedex starting some sort of mail service). Now that would be interesting. B/c technically the USPS has a monopoly. I guess the gov't doesn't play by the same rules...
It's a fun business we're in, isn't it...