Hammering the throttle does take its toll on battery life. While you can get around 30 miles (48km) of range with pedal assistance, you can expect much less when you're just using the throttle to ride around at top speed.
It's important to note that in the UK, e-bikes on public roads are legally limited to 250 watts of power and a top speed of 15 mph (24 kph). The Stealth is sold with its motor limited for use on roads, but can be derestricted if you sign a legal waiver stating that you will only use it off-road -- which is really more to cover Cyclotricity's back than yours, were you to be caught. Once signed, you'll be provided with instructions on how to derestrict, and put the restriction back on, for when you want to take it on the road.
Restrictions in the US and Australia vary by state, so do make sure to check your local laws before riding it down the highway.
Not all is rosy with the Stealth, however. The brakes are pretty ineffective unless you really jam them on -- which isn't ideal when you're whizzing down trails -- and the gears sometimes clank noisily between changes. It does leave you with the impression that they're not the highest quality components, which is a bit galling when you've shelled out £1,295.
The battery is huge, and its weight brings the bike up to a hefty 24 kg (53 pounds) overall. It's not a bike you'll want to carry up and down the stairs to your flat. Handily though, the battery can be removed, so you can park the bike downstairs and carry just the battery inside to recharge.
Overall, I enjoyed my time with the Stealth. It's comfortable, fast and relatively affordable, but it's marred by the brakes and gears, which may require you to make a few trips to your local bike mechanic after some downhill jaunts.
It's by no means the most refined e-bike I've tested, but make no mistake: it's a hell of a lot of fun.