DCFC fan here. Shame it never worked out for Porter with the Rams. He started with a real bang, had a great scoring record the first season he was with us, but what appeared at first to be an innocuous hip injury plagued him and he never regained that.
Firstly, he's a brilliant finisher in the 18 yard box- headers, scruffy tap-ins, one-on-ones he can bury. But he's not massive or fast so struggles if played up front on his own. Bit of an old school, Gary Lineker esque striker i'd say, needs someone else to feed off, so hard to fit in to any formation other than a 4-4-2 (we also changed to a 4-2-3-1, which didn't suit him at all).
Seems like a decent bloke and if his injuries are behind him and you play 4-4-2, he'll be a good signing. As others have said, he thrived at Oldham
good luck for the season ahead.