I thought this was an interesting vid by a ham on the reliability of analogue watt meter readings when on SSB.
He's not using cheap CB gear to illustrate his point, either. Bird 43 meter and a choice of 2 Drake L4-B linears (1kW FM, 2kW SSB). I'd settle for one but it would probably melt the RG58 on my T2LT at full blast. The point he makes about turning up the output to push the meter and generating lots of crap as well as "wanted signal" applies doubly to the average radio and amp you come across on 11m. A good rule of thumb for Zetagi/RM/CTE amps is to run them no more than about half the manufacturer's claimed max output in any mode. And keep the drive well down from all these nice new export radios that claim to produce 30W FM, 50W SSB etc straight out the back. You may well push them to full whack, but on FM you'll cook the output transistors and on SSB you will probably sound dreadful and very "wide".
Great channel that guy's got Andrew, very good videos and one hell of a shack.