As a silver recently promoted to gold, the difference travelling is negligible. Still fast track, seat selection, priority boarding and lounge access (which more often than not is the same regardless of status).
The move to gold has been a novelty - especially the double avios open redemptions and the higher accrual rate - but its hardly life changing. And the benefit of being able to select the front row in ET is now tainted by the realisation that the rear row of CE is reserved for those who like to recline whilst taxing on a 90 min late morning flight!
The difference, as a mainly EU in ET traveller, is hardly worth spending hard earned cash from a personal perspective unless you are a high TP silver.