Why don't we all wait and see? There are plenty of examples of players who can play at one team, and not another. From Torres at Chelsea to Lee bastard Hughes when he joined us. In the '80s, Oxford were kept afloat by selling Joey Beuchamp onto clubs he could never play for, then taking him back for peanuts.
Jackson may be a huge success. Equally, he might be a disaster. I saw a frankly astonishing post on GMK in which someone was actually thanking SISU for selling Clarke and Wilson, and replacing them with a just-as-good partnership of Tudgay and Jackson and 'saving money'. The reality being the Clarke-Wilson was the most prolific partnership, when together, in this league. Their replacements may, or may not be able to step up to the plate. Only history can prove the players to be right for us or wrong