Thanks for the replies guys - I won't quote them all as it would turn in to a multi-quote novel
Feedback on AC forums is pretty much this is what to expect with a G29... disappointing!
Had another hour and a half last night (Special Events - Carrera at Imola, RSR at Zandavoort & Cayman at Spa). The FF dead zone doesn't ruin the experience with these cars, but it does make placing the cars in to faster corners (where only minimal lock is needed) more difficult than it should be... and also managing oversteer as you have to swing the wheel through a period of no feedback.
I'm going to cut the rubber brake stopper down to fix the brake travel issue.
Had a look at T300's, and I can get one for a bit over £200... so might just bite the bullet and get one of those.