I've got quite a few of the "shiny" type (bought from Chronos), and they are spectacular on aluminium, and damn good on steel if you take it easy with the cut depth & don't let the temperature get too high.
The reason they don't like interrupted cuts is their sharp edges makes them weaker, and more prone to chipping (and carbide is already highly prone to chipping on interrupted cuts).
The "old style" that you pictured are probably TiAN (or something similar) coated, that's what gives them their gold colour. They're also quite "blunt", i.e. ideal for taking heavy cuts in steel. Remember that most carbide inserts are designed for industrial use, where time = money; so if you can hack off 1/4" of steel from a piece in one cut, that's a good thing. Most of us hobbyists - even those of us with industrial sized machines - would probably baulk at a 3mm cut depth in steel...