I am extremely skeptical of the current generation of RFID tags when used in practice out there in the wild.
About three years back I set up software to support a recycling scheme, whereby every household in a community (ca 10,000) were given a couple of plastic boxes in which to place recycled goods. The boxes where chipped *and* barcoded, and there were scales on the collection lorry to weigh the box and automatically scan the rfid chip at the same time, thus collecting usage data.
Three years on it turns out that the one thing we were not expecting - the rfid chips not to be reliable - has proven a major issue. The failure rate is not high, but we consistently have a score or more boxes needing replacing every month, which is a far higher rate than we were lead to expect. We did think it might be the manufacturer, but we've talked to several people doing similar things now and everyone has similar stories - the chips do fail.
Perversely - the barcodes, which we sealed in transparent plastic but didn't expect to last (hence going with rfid tags as major impact) have given us less than a dozen damaged to the point we can't scan them in the whole three years.