I think it's important not to exaggerate what a scanner brings to the table. Unless your train is involved in something truly significant 99% of scanner traffic is going to be automated defect detector readouts with a handful of short form dispatcher communications. These days unless a delay is caused by something controversial or emotionally upsetting the conductor is likely to relay the relevant information via the PA anyhow. I'm not saying a scanner doesn't have its place but the way some folks talk about them you'd think it was a verbose running commentary on everything your train is experiencing. Even basic scanners can cost as much as a coach ticket while the latest and greatest models can cost as much as a sleeping compartment. If you already have a portable scanner sitting around then by all means bring it along. On the other hand if money is tight or packing space is limited then a scanner is by no means necessary.
I already own a portable scanner. The rechargeable batteries have long ago been too lazy to hold a charge anymore. With all the electronics I carry, the scanner is the last on my mind to bring.
I just take a trip once a year. The only time I had a significant delay was when one of the coach cars had a flat wheel, so we had to wait in Raleigh for another car to be delivered. I believe it was the SCA who told us that.
Bruce-SSR