I'm using a seq object to record MIDI loops. I've found that when I record a loop and listen to it played back, the loop tends to rush. I checked this by putting a MIDI Quantizer on the output end. (I'm sending the MIDI data over rewire to Cubase which is hosting my plugins. I put the MIDI Quantizer MIDI effect on the MIDI track there.) I would record the loop, making sure that the quantizer didn't move any notes to the wrong beat, and then listen to the loop play back a few times. Eventually the quantizer started reacting and shifting notes around. The loop would always start on time, since it was triggered by the metro object, but by the end of each loop--8 bars long, 4/4 time, 105bpm--it would be off by about a 1/16th note value, and there would be a brief pause of silence at the end of each loop.
All that being said, is there a more accurate way of recording MIDI loops besides the seq object? The MIDI tutorial says there are many ways to sequence MIDI, but doesn't describe any of them.