I used Hotelclub to book a room for a week in Rome back in October, and have no complaints.

If my memory serves, some hotels offer quick confirmation and some may take a few days, but I think that's standard on many of the European oriented sites. My e-mail records show it took 4 hours to receive my confirmation once I had booked, and it was a near-last minute booking.

I chose this site because of price for the particular hotel--The rack rate was 500 Euros and the hotel wasn't discounting, many other engines were charging 300-350, and they had the room for 200.

One nice feature is they rebate you up to 5% of the cost of the stay towards future bookings. But when I checked them for a Paris room, they were about 75% higher than the hotel's web specials, so they aren't always the best deal. But then, I've found I can't rely on any single transparent site anyway. BTW, their US offering seem to be minimal.

They seem to be a legitimate site, and if they have the best rates, go for it.