I've run some games on a 445 with a couple of different videocards. On some games, older and/or less demanding, you can get good performance out of a 750 Ti. On newer, more CPU demanding games, you'll hit a performance limit around GTX 650 Ti/660 level.
I think the pluses, the games that can benefit, outweigh the negatives because you'd have to be crazy to try and play those more demanding games with such an old CPU to begin with.
So as long as this isn't an upgrade for Battlefield 1 for example, it's not a bad upgrade.