As Getsickanddie mentioned, and as I said before (although I don't think anyone noticed), Magma Jet is savage with Predict. UGr Gro lists should not cut good cards (Predict) to run bad cards (Mental Note). Magma Jet is better removal than Fire/Ice because it is so incredibly awesome to set up every single Predict, so that UGr Gro outdraws its white counterpart (assuming no-one is running AK).
Also, Mental Note is a bad card for many reasons, but the one I would like to point out is the milling bit. Unlike many decks, decks based on the principle of running fewer "meaty" cards and running more cantrips in order to play as if they ran more "meaty cards" cannot afford to lose cards randomly, because in many cases you only run 2-3 copies of a card you need and want to cast during any given game. Normally, it would be okay to lose random cards, but in a deck designed to run fewer threats and answers and instead draw into them, you cannot afford the likely possibility of milling away a threat or counterspell that you didn't choose to lose (Because Predict just gets rid of a card that you decided you didn't need [because you wouldn't predict it away if you needed it]). Also, blind predicts happen maybe 5-10% of the time in UGr Gro (due to Magma Jet's awesomeness), and so you rarely blindly mill cards away like the shitty mental note does. That is why Mental Note is bad.
