Here are some of their key comments:
"IK Multimedia's AXE I/O guitar audio interface is quite possibly the best guitar audio interface on the market today."
"Z-TONE DI, which takes some of its features from the AXE I/O offers you a remarkable amount of control over your direct signal."
"DI boxes can make your life so much easier you'll wonder why you haven't used one before."
"The J-FET-buffered circuit sprinkles some magic dust on your tone, livening up its harmonic response and adding a soupçon of analogue warmth."
"The routing is clever and practical. Split your signal for recording by sending your mirrored signal via the Link output to your amplifier."
"A fuss-free DI with great sound, what's not to like?"
and the final verdict was:
"Variable impedance, switchable "pure" vs FET-buffered circuit, flexible routing... The IK Multimedia Z TONE DI has a lot to recommend it."
+ Excellent sound quality
+ Simple design makes it an excellent creative tool
+ Switchable circuits