My current monitor setup is a 20" for my master and a 19" split between my 4 slaves.

Now I want something bigger, and would like some input on what to get:

Either thinking about using the 20" as the slave monitor and getting a bigger master monitor, or getting 2 new monitors.

In any case, is 24" big enough, or a bit small? What are your experiences with bigger monitors, and which brands/models are good?