Amongst the day ICE trains, this one takes the most time and hence is the least preferred. However, due to the lower length of rake size, it does gets still decently full. Come 30 mins before and you'll get a seat very easily, even window ones in some coaches. If you are boarding from intervening station, better to book in C1 rather than go standing.
Oh, and this train is often rescheduled from LKO for an ~ 1 hr or so. Check before hand. Since it has lots of slack built into...
more... it, it still covers majority of lost time usually.