I have recently acquired a new office and lab-mate. When he came in, he was asked if there was any particular glassware or lab equipment he needed. After thinking on the matter for a while, his answer was:
Thinking it over, the IKa heater-stirrer is one of the pieces of equipment that really changed how you did lab work. Of course, before there was the heating mantle and oil bath and each could be carefully set up until it gave you the desired temperature of reaction, but the IKA (and some others like it) allowed you to dial up the temperature you wanted and it worked well enough that you could pretty much just walk away and not have to worry about it.
Then you add the heating block and it goes up a notch. You can run reactions on a single plate all at the same temperature and they all stir – or at least get sufficient agitation to be mixing. The probe goes into the block, the heat transfer through the metal is pretty much uniform. Plus you avoid all the messiness associated with an oil bath. Back in the day, we had little two-by-three blocks that someone had drilled out with holes the size of the scintillation vials we used. Nowadays you can get the kit from the manufacturer with a heating block that fits right on top of the plate, with spots for 4 in the middle and a bunch in the outer ring, with other blocks to fit other vials.
Ironically, after me gushing about them for a paragraph or two, I don’t actually have one in my hood. I have a Corning version that works pretty well, but tends to overshoot on the way up and takes a while to settle on the desired temperature. I also still use the oil bath for most of my heating needs. It works OK. And the reason for not upgrading is of course the cost. If you have the $900 laying around then it is no problem, but if the budget is a concern then the IKA might not be your best bet.
They are pretty nice though.