Thanks for the above link back to my site! ;^)
I have two of those Bachmann GP-35's with decoders. I paid $35 each for them so I thought, "what the heck". They ran ok but had poor slow speed performance and hummed a lot especially at slow speeds. I tried cutting off the capacitors and resistors on the bottom motor contact, but it made no difference. So I installed an inexpensive NCE D13SR decoder in each one and they run like a dream now. Then I found out NCE makes a direct replacement decoder for these locos that would have been a bit easier to install. Either way, they are great running locos and run as good as, or better than, some $100+ locos!
Scott Jay
Bayside and Tidewater
Bayside & Tidewater Model Railroad