If you are locked into VH, I honestly can't think of an arranger VH (even the TOTL ones) that comes even close to the latest standalones.
Overall, I'm rather pleased I didn't have to pay for something I'd never use (or sound naff if I did), and that Roland allow me to pick and choose the BEST one for my needs from whoever makes it...
Overall, though, most of the Roland iPad apps are there for either editing Performances, or selecting them in the first place. So, if the app boots up quick enough, no reason you can't switch between them quickly on the gig. You don't really NEED to run two at the same time, for this purpose, at least.
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An arranger is just a tool. What matters is what you build with it..!