Things of wee stature/size probably like to hear that size doesn't matter...
In O gauge, as far as diesel electrics are concerned, I have yet to see anything as big and bold as the 80 and 90(43) MACs! I've seen pictures of EMD's DDA40X's, but they do nothing for me.
I have two MTH Premier BIG MACs, an NS SD80MAC(20-2874-1) and a CP SD 9043 MAC(20-2875-1). These SIZE-MASTERS make everything else,locomotive wise, seem appropriate for the kids table... when viewed side-by-side. Their voices seem to fit their grand physical presence, too.
My MAC's were from MTH's 2008 Vol. one catalog. I had the CSX SD80MAC ordered, as well, but I didn't take it. Re-installing the shell was too difficult...
That was the first time I pre-ordered 3 models from one page of an O gauge catalog.
BTW,I bought big from that particular MTH catalog. Besides the MACs, I went with the CP F7 ABA set; 3 ES44AC's(GE, CP and UP); a CN SD40-3 Tunnel Motor; the grey UP AC4400CW; BNSF AC6000CW and a Pennsylvania P5a(box cab).
Those were the days... lots to like.
If, down the road, MTH offers the BIG MACs in 3.0... they might be worth a look... I'd be looking at the UP SD9043 MAC and/or the CSX SD80MAC.
Rick