LR is nice for accepting payments online, while PP is good if you want to withdraw the funds. If you deal with untrusted people taking payment via LR is the best option. I use LR, PP and MB but I prefer to take LR payments in masketplaces like WSM/VMP. 
To compare LR and PP I'd say, LR is a safe box for storing money online while PP is more like a bank, we can accept payments via CC and withdraw them to our bank account or CC.
To compare LR and PP I'd say, LR is a safe box for storing money online while PP is more like a bank, we can accept payments via CC and withdraw them to our bank account or CC.