About M113 unofficial name look at this for example
http://www.fas.org/man/dod-101/sys/land/m113.htm
"The M113A1, informally known as the Gavin, is a lightly armoured full tracked air transportable personnel carrier designed to carry personnel and certain types of cargo...." So as you see, there are many people calling M113 gavin...
2mil for OHWS and C4I...Rafael makes much better and much cheaper systems,There is a M113 version with 2x7.62mm and one 12.7mm OWS.
With this armor modification is M113 capable stop even MILAN ATGM
http://www.israeli-weapons.com/weapo...13/Zelda2.html
About M113 vs M1114, you can easily mount SLAT armor to M113 without any big changes to a driving capabilities. (Stryker with SLAT is not so fast as you think,Its suspension is not build for such overweight.) Mayor Flaw of M1114 are front window, they are breakable with 7.62,broken glass is dangerous to driver, even if round will not penetrate.(As you maybe know M113 dont have windows...)
In Mogadishu fighting there wasnt even one M998 in the convoy.Most of wounded crew of humwees were hit thru the windows or when they fired from .50cal