High Level, Low lvl pc's get the same xp?

We do have our own formulas; yes, if there's a large gap in character levels, the lower level characters should be receiving more xp -- after all; it's a larger threat to them than to others. However, there is some leeway -- if the lower level characters were never in any real danger, it can be reduced or ignored entirely due to the lack of challenge.

But as a whole, yes -- if there's a large level gap between characters, lower level characters tend to receive more xp on a sliding scale.

Also -- as per someone warning. Some scenes are sliding scale difficulty, however DM's can also make scenes that are immutable -- the encounter will have more static features than none. A DM *should* give warning about that, however, they *should not* actively tell someone not to bring a lower level character because of danger. If a person chooses to bring their lower level character, so long as their aware of the potential risk that's all that should matter.

Hopefully this answers any questions that are asked.