I've got both Steve, the 71 is a backup on the Revenger, I bought the 93D to use on the SR4 as it hasn't got a fixed radio so I wanted the dsc function just as a bit of extra security. personally I think the 93 is a good bit of kit, other than the clip is crap, it just doesn't seem to be very reliable, so make sure you've got a good lanyard on it!! the 71 is still going strong, I always take it with me just in case, no wonder I need a bigger bag each season
the SH 870E gets good comments and is cheaper than the 93D .........