When watching the replay, I remember Witts stats flashing up on the screen. He'd had around 20 hitouts, with 1 to advantage, which tells me that when ROB wasn't winning the taps, he was at least making it very difficult for Witts to do anything with them.
I quite like what I've seen from ROB so far, he's shown improvement in each game he's played. He'll probably never be a dominant tap ruckman like prime Jacobs, but there's a lot more to being an effective ruckman in today's game, and he looks to have very good running power for a player his size, which will allow him to provide quite a bit around the ground.
We absolutely need another ruckman on our list, but if it's not Grundy (highly unlikely), then one or two developing in the two's with ROB taking over from Jacobs will have to do. In my opinion, there are two rucks in the league worth throwing the kitchen sink at, and they're Grundy and Gawn (even then, it's Grundy without even thinking about it for me). If it isn't either of those, I don't see it as a position worth spending much on in the way of picks or salary.