I was just gonna comment on that same fact. check the gear ratios between the trans choices because you may be surprised. maybe get you out of the hole quicker and easier on the torque converter which will build less heat which may extend the trans life etc. may make it more fun to drive too.
might be good to talk to a trans guy and see what he can do for you.
here is a write upon the 700r4 or the 4l60e. worth a read maybe?
http://www.hcdmag.com/700r4-transmission/
and another explanation with torque values etc
http://700r4.com/faq/ratiocmp.shtml
and another explanation
http://www.700r4transmissionhq.com/
here is one that shows how to ID the different units and a basic breakdown of the uses
http://www.700r4l60e.com/transmission_gm.html
hope that helps