The Hartke HA2000 is a great amp especially for the value. Even though the HA2000 is a bit older, its still a great buy. Another benefit of Hartke amps is the customer service. The customer service department has always been great in my experience and does factor in when deciding to buy any product.
The HA is full of features, not as many as the 3500 but the price is much easier on the wallet. Having a 10 band EQ allows for vast amounts of adjustment which can suit any playing style and ability. Pumping out 200 watts is sufficient for any player. The two preamps are great and sound decent but at high volumes they do tend to distort a bit.
Where the amp shines is at mid volumes. High volumes will definitely cause a distortion but depending on the style of music that you are trying to achieve this can be a good thing. Sometimes I prefer a little grit when I'm playing. If I do not want that gritty slightly distorted sound I can just bring it down a notch and problem solved. Another thing to note is the cooling fan can be a bit noisy but that's a small price to pay for such a good sounding piece of equipment.
As far as the controls are concerned, there are just so many. This can serve in your favor or against you depending on your experience level. Just keep in mind that every little knob that you play with will definitely alter the sound. If you are one of those people that must have control over every little aspect of the sound and know what your doing, then have at it. If you want to get even more particular, go for the 3500, that thing will keep fidgeting for days.
Overall a great amp, do consider that everything was used and reviewed using a Rickenbacker 4003 and VX 115 cabinets. You can pick the Hartke HA2000 second hand for a decent price so they are definitely worth checking out.