I was about to say they're expensive compared to Cubitron, but I just checked - I last bought Cubitron on Amazon at the end of March for £18.55, they're now £30.99.
Same here; where I bought them last year for £18.89 they are now £30 for 50 150mm discs.
I like the cubitron, but do find the edges a bit fragile possibly, compared to abranet. Maybe I am just not careful enough on really rough wood and corners though.
Love the ets ec-150/5 btw. Should have gotten one ages ago.