Don't know how much of a "downgrade" sound wise it is from the TLs, but I can note some other "downgrades". As much as I can tell, the Superlux is a bit lighter/smaller. Comes with three paterns (cardroid, omni, figure
, and external switches for a 10 dB pad and low frequency rolloff. About $600 for a match pair through Superlux. Don't think any recordings exist with these, but I wanted see if anyone has tried them to see what they sound like. Here is a picture of one: