A.J.
I think if really depends on your particular children. My boys are hyper and my oldest was 21 months old when his middle brother was born and we got the sit and stand and like you asked, we were constatnly chasing him around and he would not stay in it and he would get his feet stuck under it and fall when I was pushing it... we took it back and bought the COMBI side by side double stroller (LOVE IT! COULD NOT LIVE W/O IT) the Combi double stroller (side by side) fits through mall shop doors and really works great. I got mine on EBAY after looking at several in stores to see the one I wanted. I bought a brand new one much less than I would have paid for it in the store.
My oldest is now 5.5 and my middle son is 3.5 and our new son is 21 months so we use it now iwth our 2 youngest and it has really lasted since we have had it now for 3.5 years. it folds up in half then in half again and has a carry strap so it will fit in a small trunk.
HTH
A. J