I have them both... but my Pedersoli is in flintlock not percussion and my Lyman I bought as a kit and finished it myself.
The short version is that the Lyman is more robust and the Pedersoli is more elegant.
Unfortunately the way the front of the Pedersoli is held together isn't very strong and you should avoid heavy loads in it (although it is possible to reinforce it). I don't think it's a real problem but it's something to be aware of. On the flip side the Lymans as produced by the factory can be really ugly. If you can pick one out in person I'm sure there are nice ones out there but I wouldn't mail order one if you care about looks. I'm sure somebody will take offense at that and post pictures of their lovely from the factory version but that isn't necessarily typical.