Hi Marco, sorry for the slight delay replying...
The in-line's are a little more consistent in general and make the car feel much more positive and agile.
I my experience the trailing steering blocks feel very numb turning in, have lots of mid corner steering and medium/high exit steering. The mid corner steering is a very good thing but I find the point they grip to be a bit vague and inconsistent.
The in-line blocks give more positive turn in, are less snatchy mid corner but have low/medium exit steering. In general the car feels more connected to the ground, where the trailing blocks feel a bit 'floaty'.
They are very much a love/hate thing for most people, you will be able to tell after the first couple of minutes running if you are going to get on with them or not. When changing to them don't forget to space the caster blocks to the back and move the ballstud on the steering rack to the back also
Can you expand a bit about corner entry with the silver rear springs, what was it doing you didn't like, are you on a very high grip track?