"Is it a common occurrence to get infected roses when you purchase the body bag roses from the big box stores?"

Yes!

Yes, probably most body bag roses are infected. A lot of that has to do with the fact that the root stock of what ever mother plant the buds were taken from was infected and they were probably grafted to infected root stock as well.

As for the difference in your blooms I doubt it had to do with RMV but more likely was due to the all around inferior quality of the plant. Most of those body bags are not grade #1 but more likely #1 1/2 or #2 grade. Depending on where it was from it may have been badly grafted, was certainly badly handled and pretty well whacked off for packaging. Not an auspicious start for any rose. I have many virused roses in my garden and have never noticed any difference in their over all vigor. For the most part they rarely even show symptoms except in times of great stress. Hmmm...like maybe this awful winter! We'll see...

We have this discussion about RMV routinely here and there are two opposing sides. Listen to them both and make your own decision as to what you're willing to except. There are some roses out there that can not be had any other way then virused. They were more or less bred/introduced already virused since the only way they were ever propagated was to be grafted to virused root stock. Being that Proud Land was introduced in 1969 it may well be one of those. There have been strides taken to get more varieties cleaned up but it's a long road and will take some time yet before it's done. And we may lose some varieties altogether in the process. In our already shrinking rose world I hate to see that happen.

The Jan-Feb 2014 issue of the magazine of the American Rose Society has a short article titled "What is the truth about Rose Mosaic Virus? In it the author states that "Reports that plants with mosaic might produce fewer flowers or flowers with poorer exhibition form have never been proven."

See page 46: http://www.joomag.com/magazine/american-rose-january-february-2014/0521442001391189487

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The article does not mention that Rose Mosaic Virus is a group names for viruses that infect roses and give mosaic type symptoms. It also does not mention that even within one type of virus there can be weaker and stronger strains. Also, each hybrid rose variety can have a stronger or weaker immune system than another variety for each type of virus. And that the strenght of the immune system against some of the types of viruses is temperature dependent. (For these types, the higher the temperature the better the rose is able to resist the virus.)

Regarding flower quality, the actahort reference reports: "The trials were conducted in four locations under intensive production conditions during the winter months, similar to the commercial routine. In all trials healthy plants yielded over 30% more quality-grade flowers, "Super" and "Extra", than PNRSV infected plants."

http://www.actahort.org/books/234/234_52.htm

Here is a link that might be useful: link to American Rose Magazine, see page 46

Thank you, everyone.

You make a good point, Henry, about there being more than one virus under the RMV umbrella. There are a lot of variables involved and one rose with RMV could preform completely differently from another even if they're the same variety.