Thanks for pointing me in the direction of Art's review.
Yep, it is a little non-committal, but I think he's still having to hedge his bets a little because of the lumens issue.
It's not clear, but I think he's trying to explain what is a difficult comparison - the InFocus does give the JVC a run for its money, but only if you take into account (and you surely have to) the big difference in price tag.
So it is clearly not as good black levels wise and is slightly behind in some other areas, but overall (and dependent on actual real lumens) it isn't actually far enough behind to not be a serious competitor at the price.
Not sure about the "spare change" comment though, because in Europe the IN83 is actually coming in more expensive than the new SP unit.
Still, Art's review sounds promising.