To be fair to David Gunn, I must point out a few things. Yes, the through cars between Boston and Chicago were lost, but they were restored in May, including sleeper.
It is true that eastern trains are running with 1-3 sleepers today, when they used to run with twice as many. However, Amtrak used to have over 100 heritage sleepers, plus a bunch of slumbercoaches. Those were retired and replaced with 50 Viewliner sleepers. It doesn't take a math major to see that replacing between 100 and 150 (I don't know the exact count) cars with 50 cars is going to result in consist reductions.
The fact that the Viewliners are too few to fully replace the Heritage equipment (all of which was gone before Gunn came on the scene) means that Amtrak has had to run the wheels off of those cars, resulting in a fleet that ran with a desperate lack of maintenance. This culminated with the severe winter problems that Amtrak faced a half year ago, and Amtrak was left with no choice but to reduce consists and cut some sleeper lines.
Also, it is true that performing maintenance is a "no-brainer." However, the fact remains that said maintenance simply wasn't being done before Gunn arrived. Around 100 wrecked Superliners from derailments dating back to the mid 1990s languished at Beech Grove, while periodic maintenance and equipment overhauls on the rest of the fleet was stopped almost completely. Perhaps this means that previous Amtrak presidents had no brains, maybe not. But, whatever the case, Gunn is doing far more to rebuild the system than the past two or three presidents did.
Cutting sleeper lines may seem like a bad thing, but it's better to not sell tickets for the car in the first place, than to sell tickets and then have to explain to frustrated, angry, and tired passengers that the sleeping car they expected to board was bad-ordered, or wasn't even on the train to begin with because there wasn't enough equipment to go around. Certainly, there is still too much of the latter, but the effects have definitely been reduced by Gunn's no-nonsense approach, which is to not pretend that there's going to be enough equipment to go around when there isn't.
Don't forget, too, that the Twilight Shoreliner and Palmetto lost their sleepers (the former only briefly) before Gunn took over. Since May 15, 2002, one route was discontinued (Kentucky Cardinal, which carried around 20 or so passengers per day, 10 per trip, to J-ville and L-ville), and two were truncated (the Pennsylvanian, which had similarly dismal ridership numbers west of Pittsburgh; and the International, which is funded by the state of Michigan, who requested the change).
True, there have been some on board service reductions during Gunn's watch, such as the loss of complimentary sodas in the sleepers, the loss of dining car service on the Eagle south of Fort Worth, and even starting in the last week or two, or so I'm told, the fact that "a la mode" on desserts, and even cheese on the burgers, are no longer complimentary to sleeping car passengers. I have mixed opinions about the Eagle's diner, and find the other two examples to be just cheap (i.e. I don't think they're really going to save all that much money, while reducing some of the perks for their highest paying passengers).
I wasn't able to ride Amtrak very much under George Warrington (whose administration also implemented the one-menu-fits-all dining car policy, which was partially reversed under the Gunn), so I personally can't testify whether customer service has improved or gotten worse since then, but others I have talked to say that they haven't really noticed much of a difference one way or the other. You still have your good apples, your bad apples, and your "I'm doing it because it pays the bills" folks working there.
So, in summation, I guess we really can't say that Gunn has been anything more than competent in running Amtrak. But that, in my opinion, says more about how bad the previous presidents were than anything else.
BTW, thanks for the compliment.