I have a Rigol DS1054z now, and a Instek gw GOS-6112.(2 channel 100mhz analog) I do find that they are not very useful at higher frequencies.
IS the Tek 2465B worth having on the bench? $500 to $700 for a good working scope of 400mhz seems pretty good compared to later units.
Useful to do what?
To look at signal shape in the time domain, i.e. signal integrity: yes.
As a pleasure to use: yes.
To look at RF signals: possibly, and possibly better than a low-end digitising scope. But would a spectrum analyser or modulation domain analyser be the more appropriate tool?
To capture rare events: no.
To to post-processing in either the scope itself or on a PC: no.
To analyse digital messages: no. Use a logic analyser or printf statements.
If you do decide to get one, make sure it is working and the calibration constants are intact. Ideally the PSU and A5 board should have been recapped.