they are!! however as with all things to do with this hobby, there are complications :woohoo: nothing to worry about
but you must be aware of them, cost is one thing they are quite an expensive bit of kit but you probably know this already :S but still worth it,
2nd, is to do with the type of roller some are gritted and this can wear down replacements are not cheap either. others have grooved aluminium last longer but are even more expensive.
3rd, you can have problems with wet/muddy tyres causing roller slip as they use friction between the rollers and the tyres
4th, they can sometimes object to climbing a step (like a 2/3in drop kerb) face on!! one has to either go at it on a angle or use a ramp
5th, the hand sets have a limited range so it is possible to get too far away from the van loose signal and the van stops!! good news is walking closer and restarting works!!!
John has outlined the power consumption nothing to add except I use a car battery because the vans always on EHU but I did mention that in a earlier thread