I've ridden a Toxy ZR for a couple of years, not massively impressed with FWD compared to RWD, but it works. The "magical mechanism" which "allows the chain to twist" doesn't really exist, as on this bike it's just a couple of idlers and a chain 1.5 or 2x the normal length. What it means in practice is that you are severely hampered eg coming out of a T-junction, it often is easier just to get off the bike and move it by hand, the steering is extremely restricted but works well enough on the open road but would be a pain negotiating tight bends eg on an audax.
The front wheel tends to slip on hills, I recently got up Edge Hill on mine which must be 1:5 in places but it will start going at 1:8 in the wet, and when the surface is bumpy you always get a bit of intermittent slip.
I got round the heel interference by installing a 3cm shim on the right pedal, not ideal but has been OK so far.
All-in-all a bent for £1200 that weighs 12kg and is a folder is a good buy, I'd go for it on its own merits and just looking for a link I saved for a Berlin bikeshop that was selling one that weighed 15kg and cost a lot more, now vanished ...