Whether the 44 is worth spending money on depends on your expectations and reasons for doing so.

In my book the only reason for keeping a standard one is to aesthetically match a Quad power amp as I don't rate the sound from the 44 or 34, I find them bland.

If there are upgrades available to improve the sound it may be worth looking into, but I'd certainly not put hundreds of pounds into one. I think the money would be best put towards a better sounding pre-amp.

If you're interested, the Promitheus TVC pre-amp sounds very good with Quad power amps. I'm using one.