For straight ahead live capture, the H2 or H4 both are quite excellent (I've used both, have the H2 now), especially if you do 24/44.1 wav to start off with. But if you want to make anything other than a 'direct to CD' live album, a computer DAW gives FAR more opportunity and ease of editing.
Yes, you CAN overdub with the H4, but little you can do with it afterwards, nor punch in and out to spot fix problems - everything has to be done in one entire take. Unless your goal is a simple 'one take live, warts and all', a DAW gives you a much better opportunity to do stuff like apply a GOOD compressor to the voice (built-ins on arrangers are anything but!), de-essing, high quality reverb and tempo based echos (all, again, at FAR better quality that built-in effects), and also to use high quality condenser mikes, which are unsuitable for stage.
Not to mention simply punching in on one section you might have got a bit pitchy on or overcooked the take...
One feature that the Zoom's have is the ability to act as an audio interface for a computer DAW. If you haven't already got one, these will get you started quite well, and with a program like Cubase LE, or Sonor Lite (or whatever it's called) or similar things, and open up the possibility of recording something FAR better than a simple device like the H4 or H2.
They make excellent live capture devices, but really don't have all the tools and capabilities they need to make a pro quality CD (unless it's a basic 'live at the gig' recording), IMO....
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An arranger is just a tool. What matters is what you build with it..!