Understand what you say, and I think it depends on what you enjoy.
Personally I like the big event because it is such a massive challenge. Not just logistically but car preperation and mentally too.
Whilst short two day events are fun, I find it difficult to get into full competetive mode, and hence tend to treat them as "fun". This is likely why my "face" appears different at Targa, I'm mentally preparing for it a month in advance. That is not to say that I haven't got to the start of day 4 and wished it was over soon, or had thoughts during a touring stage whether I'd come back.
I guess, and I know this sounds full wank, but to me, a two day event is a walk along the beach, Targa Tassie is Everest, if you complete it, regardless of where you finished, it's seriously satisfying.