My board is a system 'board' inasmuch as it's fully symmetrical. It 8x8 foot 35 degrees, and has 4 different sets of screw-ons/lego bricks for footholds, and about 140 handholds. I tend to set hand sequences, master them both left and right, and then work them on the different footholds which get progressively smaller, less positive and widely spaced.
The main benefits I've noticed from its symmetry is I can often do a move one way and not it's mirror, and have much greater hand accuracy (eg throwing to a pocket) with one hand. It's allowed me to discover these issues and tackle them in a structured way. I also video myself to compare shoulder stability on maximal moves, and generally notice variations in movement habits between my two sides.
You're welcome to come and play on it if you're in the Kendal area, and as I've just switched focus to route climbing (ie bigger holds), I have about 15 pairs of small symmetrical handholds going spare.