I have owned the Aegir for 2 months. It will drive efficient speakers to high SPL. The sound is very detailed and easy to listen to. The price is awesome for this performance level. There is another small manufacturer, Monarchy Audio, that I considered. He/they have been in business for a long time and the reviews I saw were good. 25W all Class A with zero feedback. The price point is below the Schiff($719). He also sells monoblocks. The small First Watt and Pass Labs stuff is also good but cost much more. I am interested in tubes as well but am not ready to start buying multiple pieces.
Good used tube amps will cost more but I would like to hear the Dennis Had amps. I have not seen very many bookshelf that are over 90 dB and the Aegir would not drive these to full bloom. I guess it depends on how loud you want to listen to these. I didn't look up your Accuphase but if it is small Class A and sounds good I would keep it. Their stuff has always been highly regarded.