Most likely similar to Boss. Buffered bypass does suck tone to a certain extent. 1 or 2 pedals may not make a big difference but the more you put the more tone is sucked.
Consider this anology.
True bypass: 10 monkeys are standing in a line. These are all true bypass monkeys. You pass a message on a piece of paper to the first monkey. He passes it to the next, and the next, and the next. So the last monkey gets the exact piece of paper you wrote.
Buffered bypass: Another 10 monkeys are standing in a line. These are buffered bypass monkeys. Each of these monkeys have stacks of papers and pens. You pass your message on a piece of paper to the first monkey. He looks at your message, and tries to copy it as exactly as possible. But being a monkey, he'll never get it perfectly the same. He then passes that message to the next monkey, and that monkey copies the new message, and so on. So the last monkey will get a 10monkeyfied version of your message.
However this is not a worry when your pedals are active, only when you are bypassing them.
Consider a distortion monkey and a compressor monkey standing in a line. If you turn them both off, then they are your typical true bypass or buffered bypass monkeys. If they are on, then the distortion monkey will take your message, copy it, and add lots off scratchy lines everywhere. Which is what you wanted it to do anyway. The compression monkey will then take the distroted message, copy it, but making it stay within certain boundries of the paper, which is also what you wanted it to do.
Make sure to feed your monkeys their bananas. They do lots of weird stuff when they don't get fed enough.
Edit: I forgot to say one thing. Its good to have one buffered bypass pedal or any buffering system right at the start of your chain. It strengthen your signal which can then travel a further distance through your pedals or cables with less treble loss. This is because of impedence and capacitance and some other technical stuff you might not want to hear.
