Hi Will,
I am answering this question in a new thread because I want to keep the battery capacity vs voltage thread on topic.
Your question is a tough one because neither the Sanyo 1100SCR cells or the Eflight 1500 cells are made to take the punishment you are putting them through (73C and 53C discharge respectively). Because of this it may be a waste of time to go into any detail about each cell. Try your best to keep them cool and keep the flight as short as possible.
With that being said, in my opinion you will get better performance from the Eflight 1500 cells because they are the best in the 2/3A class. They are also smaller and lighter than your 1100 cells (an added bonus) and would be a fresh cell, rather than your old 1100 cells, which sound like they aren't going to deliver their max performance anymore.
The Eflight 1500 cells can be found at
www.cheapbatterypacks.com for $2.50 a cell along with a discharge graph. They are also reviewed in the September issue of Quiet Flyer.
As for the cell condition you may have over charged some cells (HOT) and not fully charged others (cold). If you want to find out their true condition you can try charging them at 1/10C or .11amps until the pack is fully charged or better yet charge each cell individually. Once fully charged, discharge the pack or cell(s) to find what kind of capacity it is delivering. If it is considerably less than 1100mah your cells are shot.
If I were you I would buy new cells knowing it is a fairly cheap investment for a fresh start. But, you also have to be comfortable knowing you may trash the cells after a few flight from the high discharge. If you can handle a little more weight go with a larger cell. In the end it's your call.
Mike