No, only temp sensor is the one right behind the filter. I don't even have any instrumentation.
There are some well-documented setups on Saturnfans.com that are much closer to the exhaust manifold and produce higher temp air. Apparently the point at which the stock pcm starts to retard timing is quite high for most operation (around 150+ F). I may borrow my roommates scangauge/OBD2 reader/whatever to verify I'm not in the crazy temp range, but I'm in no rush.
Unfortunately, there is really no reliable way to A-B-A test anything around here since the nearest traffic free section of road is probably over an hour away, unless I feel like doing my testing at 3:00AM. I'm happy with just logging my mileage as usual for now - after all, its gas usage that I'm really after. Even if its a placebo that makes me subconsciously drive better... I'll take it
Your post did make me think about the intake manifold a bit... the stock manifold does have a coolant line coming into/out of it. It would be quite easy to add another heat exchanger in-line to extract more of this energy if I so desired. Although, as I pointed out above, the only intake air temp sensor is near the filter, so the computer compensation wouldn't be as accurate.