PTheory
They aren't comparing it to Ableton (that was me having just started dabbling with Ableton) they are just saying that it doesn't do anything extra that all other DAW's can't and in fact the integration and workflow suffers compared to most other DAWS
Can't see how Ableton and Sonar are so different they both do exactly the same job which is to record, sequence and mix audio and midi
I just read the review and it seems to be a good review to me. SOS isn't like some of the other magazines that give positive reviews to everything. They, along with Tape OP are generally pretty honest and can be brutal on occasion.
As for Abelton vs Sonar, it's a matter of workflow. Abelton is great for putting together songs via cut and pasting, inserting and manipulating loops and so forth. It's geared more towards people who are not recording live instruments, not that it can't be done, but it's not the best tool for that.
Sonar is the opposite in fact.
Both of course have a huge overlap, but their workflow makes them compliment rather than replace each other.
That's just my 2 cents having worked with both.