I guess if the non-isolated ones are so cheap you could always add one if you run out of outlets on your T-Rex or whatever. I have used up mine with the following:
Two pedals (wah and polytune) on a Y to #1 9VDC
Five pedals (phaser, compressor, 6-band EQ, distortion, overdrive) on a daisy chain to #2 9VDC
One pedal (power-hungry ISP Decimator G-String) to #3 9VDC
Two pedals (in the loop, boost and 10-band EQ) on a Y to #4 18VDC
Two pedals (in the loop, delay and chorus) on a Y to #5 9VDC
Of course you have to know the mA draw of each pedal. All of mine work out fine.
I bought the three Y-cables on ebay