Hey,
There are a ton of advantages with using MTC, and these are why so many people use it when transferring data from one device into another..
1. There is error correction built into MTC. MTC is made up of a series of 'quarter frame messages' which tell the recording device what position in the source cursor is in. If any frames are dropped, the recording device is smart enough to know to jump ahead and make sure the rest of the audio being recorded is where it should be on the timeline.
Think of it like this: MIDI clock is like a metronome, MTC is like a real clock...if I want you go outside and run from 1:00 pm till 3:00 pm, it would be super simple knowing when to start and stop because I would look at my watch, which tells me EXACTLY what time it is. I would know when to start and stop just by looking at the watch...
If I tried to do this with a metronome, I would have to know in advance what the time was, then I would have to count in my head all the clicks it would take to go from 1:00 pm to 3:00 AFTER I decided how fast I wanted to do my counting (MIDI clock is tempo based and therefore not fixed).
2. Because of the inherent time placement of MTC, when you dump tracks into a program like PT, all your tracks will line up perfectly. As MIDI clock doesn't have this built into it, you risk having to manually place each track next to each other to make sure that they are all lined up.
Just a thought...although I don't know what your sequences are like, I will assume that a lot of it is repetitive. With this in mind, why not just record each pattern and copy-paste them across the timeline in PT? This way you don't have to worry as much about drifting and it will save space on your hard drive.
Take care,
Nick