I recently picked up a Sony S500ES tuner. Very nice, and good price second hand. Reception is good, balanced outputs, solid build.
Not tried any Kenwood tuners. Though I have a Hitachi FT5500 Mk2, which is very good too (again cheap second hand). Previously I had an Arcam Alpha 7 and 8 tuner, both nice smooth sounding, but not very selective; Sugden R21, classic late '60s solid state tuner, lovely sound, but could only tune upto about 102MHz; a Leak Delta Tuner, again not bad, but limited spectrum; Denon 380RDS, pretty bog standard, bit bright sounding, good granularity but didn't standout.
Sony or Kenwood? difficult choice, depends what's available to you right now on the market. The ES stuff, does carry bit of kudos and rep, so may have better resale value in the future. Whereas the Kenwood's strengths are more down to those in the know.