I'm attempting to use my naff Halfords Apollo folder, and am close on giving up on it, brakes suck, the front bars are getting increasingly loose, the whole chainset is making way too much noise, and its just a total p.o.s.

So, I'm starting to look around at what to replace it with. I currently do about 12 miles a day, and have to fold up the bike for use on the train for the commute to work. Also, coming up in July, I'm going to be doing the London-Brighton bike ride for the bhf, along with a few other guys here in the office.

I'm wondering if its worth either getting my mountain bike sorted (which will mean a whole new chainset, tyres, brakes) for the ride, or getting a folder that will handle the daily commute, and will also be good for 50+ mile rides.

I've not got a massive budget (probably circa £300), and from browsing various sites (and e-bay), have compiled a list of possibles.

Downtube IXFS. Possibly my favourite, but not sure about 16" wheels over such a long ride.
Dahon Espresso/Jack. Definitely better for the longer rides, but not sure if it will fold enough for the train.
Dahon Speed D7, or Vitesse D5. Both seem pretty good.
Giant Halfway. not read up much on it though.

The odd one that I've seen is the Dahon Hammerhead. I've seen the Hammerhead 5 going for a good price, but its confusing. Its always listed as a folder, but the frame looks fixed, so does it fold?