Only thing with that is they sometimes employ MyHermes as the end courier. MyHermes is simply THE WORST courier for negligence/damage and not caring afterwords. I speak from multiple bad experiences. I wouldn't use them if they where the last courier on earth.
parcel2go is just a comparison site, they'll only use myhermes if you select them. I usually use parce2go but select someone like parcelforce/fedex/tnt/city link/ups as it's usually cheaper than going to them direct. All the couriers make mistakes, but I tend to go for the ones I've heard of. I wouldn't use yodel either. I have also used collect+ for sending within the UK and that actually went ok and was cheaper than royalmail.