Yeah from what I understand for the PS4, the patch for retail discs was around 45GB, the digital download is around 90GB as that's the patch and the files that would have otherwise been copied over from the disc.
On another note, any PS4 users able to confirm whether the gold/ultimate bonuses are tied to the PSN account specifically or the console instead? Different games implement it differently so just wanted clarification if anyone has family/other accounts that have tried TD2 on their console and whether they got the bonus content.