Similarly I have not heard the Hegel amps but have owned several integrateds at various price points in the past. The Luxman L-590AXII is the costliest integrated amp I currently own and it is a very good Class A at its price point. It is rather neutral and balanced for a Class A design with good detail, slam and dynamics when properly matched to suitable speakers. Currently I have the Luxman matched to Marten Duke 2 and the combination is quite stellar. The Luxman outperforms a costlier Naim separates in my system. If you desire a bit more slam and dynamics (instead of a lusher and more tube-like presentation of the L-590AXII), you can opt for the Class AB L-509X. The good thing about the L-590AXII is it doesn’t sound too ’tubey’ or warm although it is a Class A. The clarity, detail, slam and dynamics are still great for a Class A.
Personally I feel it is difficult to beat the quality of the Luxman unless one goes higher up the ladder with say the Vitus or Gryphon etc., or the top-of-the-range Accuphase, but then you would be paying twice the price or more with these high end integrateds. There is also the Pass Labs but not sure how they compare with the Luxman. At this level I don’t think you will be disappointed with any of these amps although they may have some differences between them in their sonic presentation.