Quicksand for the masses. Rover Algorithm lets you upgrade any ice so that it grows in strength the more the runner goes through it. It's ideal for making gear-check ice on heavily run servers (HQ, R&D) scale into the late game.
The actual impact on the game depends a lot on the strategy your opponent is playing. A player which runs rarely but focuses on heavy multi-access (e.g. R&D Interface or Deep Data Mining won't sweat the Rover. A run-often player such as a criminal with lots of run evens like Account Siphon on the other hand will find that their runs will become quite costly.
Because Rover Algorithm stays when the host ice is derezzed playing it on a cheap ETR barrier means that even if criminals pull their derezzing tricks you can still rerez the ice at boosted strength. On the other hand ice destruction will still work well, though Parasite of course is somewhat slowed down due to the boosted strength.
There is a slight difference with Quicksand in that Rover Algorithm boosts strength after passing while Quicksand does so on encounter. So the first time the runner encounters ice with Rover Algorithm it's not boosted yet. In the long run it doesn't matter but it makes Vanilla plus Rover Algorithm even worse than it already was (two cards instead of one) compared to just plain Quicksand.
Overall Rover Algorithm is a useful card in many circumstances, it's available to everyone and has a fair price. I don't think it's overpowered but it's certainly worth considering for your next deck.
Yesssss let´s get 3 rovers on one ice and watch the runner´s face as the ice gets +3 str when they get past it. Also you can use Sandstone - 3 rovers would get it only +2 str everytime, but if you get the rover onto sandstone before you rez it, it gets permanently patched (well, considering the play cost and click needed for the rover, the sandstone´ll actually become a 6-rez 6-str etr ice, buuut you can still pull off your Reverse Infection combo so it´s definitely worth the deck slots)— m.p