I went on lots of test drives a few months back also choosing a company vehicle.
On paper, the 1 series wins. Low lease cost (low depreciation and running costs) and so the 120 M-Sport works out cheaper than the Leon. However at test drive, I could not believe how low rent it feels and also accommodation is woeful.
I then tried the A3 Sportback - sales person was an arse, plus the passenger footwell legroom was very poor.
Golf GT TDi was next - very good. I hated the Mk5 Golf as the handling was awful IMO - far too heavy and the suspension and damper set-up emphasised the weight - it actually felt heavier than my previous Lexus! Anyway, the Mk6 is set-up much better, is better on economy, the interior is good - all nice.
Leon FR next - not as good on economy, not as good on residual cost or servicing cost - so works out more costly than the Golf. But a hoot to drive.
If a private purchase - I would have gone for the Golf as I already have a weekend fun car, so my 'daily driver' doesn't need to be 'special' and the Golf would do commuter duty well. But since someone else is picking up the servicing bills and depreciation - I have gone for the Leon FR.
The Leon and Golf were both significantly better than the A3 and BMW though. IMO.