That is correct about giving you a quit claim deed but that is only after the redemption period is over and the taxpayer not only doesnt redeem but also doesn't file a lawsuit challenging the legality of the sale.
The IRS probably doesn't care what happens after the sale just as long as they get their money...I assume all they are interested in is recovering their losses and what happens to the investor after the sale isn't their problem..therefore they aren't hopping up and down to answer questions on the matter
I also have read that this is a VERY confusing part of the law...and could potentially be very costly for the investor to protect their interest...because all they really get during the redemption period is a certificate of sale...the taxpayer is still the owner of record and could sell the property. Now, you can record the certificate of sale but that would only inform anybody pulling title that there is a possible break in the chain of title.
Also, once the sale is over and there is a successful bidder, the IRS lien is released and will not show up on title anymore...
Knowing all this...i'm not so sure this is a profitable investment...too much legal hassle...Also I think a bankruptcy may discharge your certificate of sale.