@hsmamato2 - In order to book a partner award, the airline you will be physically flying on would have to have saver or off peak award availability. It is possible that the dates you are searching have no partner award availability. I saw you mention earlier that it is too late to open an Iberia account and wait 90 days so you can transfer Avios over to book your flight directly on Iberia, so your travel must be coming up. It is possible that any partner award availability Iberia released was already booked.
Yes, we have flown on BA using Avios to visit many international destinations. I only fly BA up front for European trips due to the taxes and fees. I know I'm going to connect through London and pay out the ying yang in taxes and fees. So I view my BA flights in terms of paying less than an economy ticket price in fees and using my Avios points to upgrade myself to first class. Avios is a distance based program so for most people, the points are best used in domestic short haul flights or short flights within Asia.
We are also booking our award flights the day they become available, thus increasing our chances of securing award flights. This is why I have always recommended on this thread to plan 2 years in advance. One year to secure points so that they are in place to book flights one year before you travel. However, even 330 + days out an airline may not release partner availability if it is a peak travel time. This happened to us for booking the Antarctica trip. But I knew it likely would. At the 2 years out mark, I had checked flights for the time frame we'd be traveling. There were no saver awards so I knew I would not be able to use Avios to book a partner award and I'd need to have 345,000 AA miles per person in place at a year out.
You can always call BA and see if they are able to find you an award flight. Can't hurt to try.