Having recently raised a seed in the UK; there is simply no reason to accept any sort of prefs for a seed round. There is plenty of SEIS/EIS money about - and part of those tax relief schemes is the investors need to take ords or they lose the tax-relief.
And generally the UK is stricter on multishare classes - and approved share schemes have some strict rules on what sort of shares employees must be issued with.
Your mileage may vary etc.