which areas have you been offered one? If we can narrow it down a bit, but depends whether being closer to open water, or being more sheltered is a priority?
Right now I am only aware that there seem to be moorings available in Holes Bay, near the main channel opposite Brownsea and also in the North East corner between Sandbanks and Parkstone.
Pref to be close to the harbour entrance but my guess is that the North East corner is more exposed
Holes Bay restricted for access by the bridge. Anything either side if the main channel is exposed and can be rough. Also tide runs quite hard. North east is a good location as out of the main traffic, but a lee shore and again the tide can run hard. however, close to harbour entrance which saves 30 minutes or so compared with Hamworthy. Key issue is shoreside access for dinghy and car parking. My favourite for many years was just east of Salterns at Lilliput Yacht Station - now apartments and no access. With shallow draft Parkstone Bay takes some beating.
Anything the wrong side of the bridge will soon be the wrong side of two bridges. So Holes Bay not ideal.
Car parking is a must. Moor as far away from the main channel as possible. Can be rough for a small tender almost anywhere, so shortest possible row or ideally launch service.
It would also be nice not to be near any turning point for the looney racers to minimise the possibility of anonomous bumps and scrapes.
Mine's at Lakeyard Hamworthy - think they still have spaces (includes free water taxi at w/e). A bit far but quiet and calm (generally)! If you join the club free parking and excellent food as well!
We spent half a dozen happy years in the Wych Channel, off Brownsea and three at Lilliput which was far more convenient but sadly no longer available. I'd be wary of moorings offered just off the main channel as they cut up rough both from traffic and tend to be exposed to the dreaded east wind which turns Poole harbour into rough spot if above f5.
The Wych is a lovely quiet mooring but does require a biggish dingy to get to as it is about a mile from the nearest place to park but in my view worth the effort as you can spend the night on the boat away from the madding crowd with only sea birds for company.