Regular fliers from Gatwick and Manchester which 747 aircraft that are due for a refit you have flown on, would you say in your mind has had the most unreliable IFE ? For me in PE its got to be English Rose first aircraft into Vegas from Lgw after the ash cloud cleared faulty IFE for return trip! Twice last year waiting at the gate in Vegas for a return flight to Lgw a call to the podium and a £25 voucher for Virgin due to no IFE. Now i have a flight from Man to Las on 29th March 12 and i see yes English Rose is flying that route!
It is still way to early to even think about predicting which a/c will be operating which flight in the 29th March.
All of the LGW/MAN fleet rotate, so it won't probably be util the day before when you might be able to predict, but even then a/c changes happen on the day quite often.
Thankfully, and I know it won't affect your fight unfortunately, but the refits will mean brand new IFE for all the LGW fleet, so fingers crossed no more issues.