Hafler XL600 Vs Hafler 9505 Much difference?


Hello all, I am new here and still learning to navigate the website. I have been out of audio for a number of years. I had an old Hafler XL600 years ago and really liked it for the price. I am thinking of getting into audio again and am considering purchasing either an XL600 or the newer Hafler 9505/9500. I have read there have been a lot of improvements in amplifiers in the last decade. Is that true? How much difference is there in the amps I am refering to? Would I notice a difference between the XL600 and the newer amp? I hope to purchase Boston Acoustics VS336 speakers to go with this.
Any info would be helpful.
Thanks
sundriednm
Talk about a trip down memory lane; the Hafler 9500 and 900 series pre coupled with a pair of Acoustat welcomed me into this wonderful hobby 28 years ago...

Wig

     I wouldn't use Schottkys in these amps either; especially since both rectifier bridges (L&R channels) are mounted on the front of the horseshoe shaped heatsink, very close to the outputs.    BUT: some people swear by them.

     I've used IXYS HiPreFRED and FREDs, in quite a few upgrades (my own and others'), with excellent result.