In my current campaign (scen 17 as Allies), I began with the strategy of maintaining PM while quickly seizing and building up Lunga and Tulagi. Spent the whole month of May doing just that. Thousands and thousands of infantry and support troops at Lunga/Tulagi (LT). Airbase at L was shaping up nicely with bombers being able to fly out and wreak havoc at Shortland by late May. Carrier TF parked NE of LT as mobile cover (Zuikaku already sunk, supposedly), just out of reach of Rabaul LBA. Things were good.
Then came June...and a hard lesson learned...
...He who controls the Slot controls the Solomons - and the Slot is a MUCH safer place - in May/June at least - for the IJN. Reasons:
1. Rabaul LBA can reach the length of the Slot, providing overwatch for anything friendly that comes down the Slot - or punishing anything enemy!
1a. Corollary to #1: the IJN CVs can reach out and touch T-L without exposing themselves (makes it incredibly difficult to keep the place supplied/supported!). They simply remain under Rabaul cover. To close within striking range of them is to enter LBA range. No, no, no.
2. In the first stages of the campaign, the IJN is clearly fielding many more capital ships than the Allies. In fact, the first BB for the Allies is not expected until mid-August or later in my game. Several IJN BBs have been spotted already - some engaged (Hiei is sunk, supposedly).
3. The implications of the 3 points above: early in the campaign, the IJN can send MULTIPLE massive heavy ship TFs down the Slot, covered by large CV forces (with all the Slot being covered by Rabaul LBA), and wreak devastation upon T-L. Apart from forming CA-heavy 'suicide' TFs to blunt the assault (or risking the Allied CVs), there isn't a whole lot that the Allies can do at this stage.
I may have to abandon T-L for now and concentrate on New Guinea.
I see why its called Iron Bottom Sound

Ricky