I have a new-to-me LeCroy WaveJet 334 and I had intended at some point upgrading by getting the LeCroy Logic Studio but I find LeCroy have set things up in the following bizarre way:-
The WaveJet 300 (not A) series have a USB port but it is "not operational" (I suspect this is firmware rather than hardware).
If the port on your Wavejet 300 is not operational then it is defective. Both 300 and 300A have USB 1.1 ports, and the 300 manual lists how it can be used to store waveforms on USB flash drives.
And it's unlikely to be the firmware as both 300 and 300A seem to use the same image.
I guess the main reason why the LogicStudio lists the 300A as requirement is because the WaveJet 300 is no longer supported, and if a product is no longer supported then a manufacturer won't test new products like the LogicStudio for compatibility with it. And that's not just LeCroy, any manufacturer does the same.
There is really nothing bizarre in this in any way.
However, I wouldn't be surprised if you find that LogicStudio works just fine with your Wavejet 334 (maybe just needs the latest firmware), with the only disadvantage that if you run into troubles then you're on your own as you would be running an unsupported configuration.
(OK when LogicStudio came out the A series had been out a while but it doesn't fit in well with LeCroy's statements about providing long term support to their products.)
IIRC when LogicStudio came out the WaveJet 300 was already out of support, and as the Wavejet non-A must have come out around 2003-2004 and was retired around 201072011 that makes still for 7 years of support.
Also, don't forget that the WaveJet Series is a upper entry level product, and you can't realistically expect the same support as for a midrange/highend scope like the Waverunners or LabMasters. Not to forget that the WaveJets were designed by Iwatsu.
Again, this is normal practice. Go to Agilent or Tek and you'll find the same. All the options of the Agilent DSO-X2000 Series won't mean a thing once it has reached EOL status.