Max/MSP has a much broader set of built in nodes, a full set of MIDI tools, a graphics toolset, a defined order of execution, different data types including tuples, a debugger and a tiered processing model divided between Max nodes which run at sub audio rates and MSP nodes which process audio. The stand-alone version can produce plug-ins, and other redistributables. As a modeling language, Max has a wider scope, probably offers better performance, and can certainly create things not possible in Audulus. Its also $399 so it’s a bit unfair to compare the two. Max/MSP would be the tool I would choose if I were coding with a specific application in mind, it’s definitely the heavyweight in the audio DSP field. PD is actually a pretty nice application, particularly for the price. It’s a bit limited in some areas compared to the others.
I don’t really have any experience with Reaktor, Bitwig or TouchDesigner. I looked at Reaktor and Blocs certainly appears to be a capable app, but overall, I just found Audulus more fun. As with any programming environment, I sometimes wish for capabilities that aren’t available, but overall Audulus satisfies my urge to tinker. It’s simple and elegant without a lot of constraints
Timing issues typically arise in things like sequencers or other counter-based modules, particularly if there is feedback involved. Two gates that are intended to happen together, won’t. One will precede the other and there isn’t any way to predict which it will be. You need to code defensively so that simultaneous events that interact don’t occur.
Here’s link to short tutorial about data values, the expression node, and the operator order of precedence. The Audulus Expression Node
No iteration I’m afraid and and only a single output from an expression. No debug mode either, although you can get a display of the relative CPU usage of the modules in a patch. I’m afraid you just have to dig in and figure it out.
I wasn’t sure if you were on a Mac or iPad, but you might want to consider an external scope application. For the Mac I use oscilloppoli and SoundFlower to rebut the signal from Audulus. I know there are a couple of apps available on iOS as well.