My Mrs has one, a 14 plate Zetec. It's nice to drive, as the OP said it is a bit gruff at low revs. There is probably not that much torque at low revs. Once it's running, it's a decent little engine, much better than the NA 1.6 with 85 bhp. Being a Ford it is good to drive. The handling and ride are better than my Astra K. It's been very reliable despite what commentators here suggest. It is on 70 k miles. Economy not great, w audio get around 42 mpg but we first got it I drive it like a nun add got 70 mpg round the M25 so it is possible to get good returns.

The 'commentators' simply point out that the engine has a less than steller reliablity reputation, which is true. Ford have sold an awful lot of cars and vans with the 1.0 Ecoboost, and obviously they are not all going to go pop. Probably fair to say only a small percentage will have problems, but because of the numbers involved, that small percentage is going to be an awful lot of vehicles!. If buying new and planning to get shot of it before the warranty is up?, i'd be quite happy to have a 1.0 Ecoboost. But 2nd hand?, there are other cars available with much less chance of causing you grief, one of which is where i'd rather put my money.

BTW, the n/a 1.6 has either 100bhp (1st and 2nd gen) or 125bhp (3rd gen). you did get n/a 1.4 versions of the 1st and 2nd gen Focus, they had 75 and 80bhp respectively.

I'd take the 125 bhp 1.0 economist every day regardless of real or perceived unrealiability.

That is entirely your choice and good luck to you. But your own experience and opinion on the engine doesn't mean that potential buyers considering a Ford with it shouldn't be forewarned about the failures experienced by many others.

And let me ask you this, would your opinion on it be the same if your engine had gone pop, Ford told you it was your own fault, and left you to foot the bill?.