Actually,the game looks better in the mac version.Its true.
Yes mac version is excellent.Fully compatible with pc players for mp and game saves.Been playing on mac versions for years.Only recently got a pc.
Yes you can play all the scenerios that require FW if you have MGE......but

.....pc uses different file types for stuff.Like, instead of .wav for sounds they are a different format- .aiff
Same with .gif.Mac uses .pict or whatever.There are a bunch of different font types and sizes also.
Having said that,scenario conversion is not that tough.There are extensive instructions at Apolyton in the MAC section.And 2 converters that do a good deal of the conversion work for you.
click
There is also the largest selection(afaik) of scenarios allready converted and ready to go..including..imo..the best scenario ever made..Red Front...complete with a delete events and applescript for loading the different seasons.The delete event(delevent.exe) is most critical for playing any scenarios that have multiple rules,units,events etc.At the start of each scenario part,you must clear the save of all previous events.Thats what it does.