This is a difficult question to answer, because it depends on where the other people in the MEARS shuttle are staying. TTC is just for your party alone.
TTC should take about 30-40 minutes from MCO to the GF.
We've used TTC several times in the past three years. Most of the time it has been only a party of two. We like the luxury and convenience of being the only people in the towncar (except the driver, of course, LOL). We go straight to the Hotel (unless we decide to take advantage of the 30 minute grocery store stop). I will never take a shuttle again - I don't like being one of 10 or more passengers and I don't like stopping at other places before mine. (I know, I am spoiled)! It is a great way to start your WDW vacation, though.
In the end, this is truly a personal choice. For many, the $$ savings is more important than the hour or so of extra time getting to their destination.
Congratulations on your marriage and best wishes for future happiness. Whatever you decide, I'm sure you will have a great trip. Enjoy!