Ambrose's biography of Eisenhower goes into a little more detail. Some relevant excerpts from Part I:

But Eisenhower's distinction between his methods and McCarthy's was much too fine to have a public impact. What people wanted to know was, Would he repudiate McCarthy or not? What made it a major question was not just McCarthy's popularity with the right wing of the party, and indeed with Republicans throughout Wisconsin, the Midwest, and the West, but more to the point, McCarthy's assaults on Marshall. The question became, in other words, would Eisenhower defend Marshall?

Now in fact, Eisenhower had already done so, in his August 22 press conference in Denver, and would do so three more times during the campaign, in Salt Lake City, in New York, and in Newark. But neither Utah nor the East Coast was Wisconsin...

In late September, Eisenhower flew to New York for strategy sessions before embarking on a train trip through the Midwest. After Illinois he was going to Wisconsin, which meant that the question of what to do about McCarthy had to be faced... Eisenhower said to Emmet Hughes, "Listen, couldn't we make this an occasion for me to pay personal tribute to Marshall - right in McCarthy's back yard?" Hughes, a self-styled liberal in Eisenhower's headquarters, was enthusiastic. He drafted a paragraph that praised Marshall "as a man and as a soldier,... dedicated with singular selflessness and the profoundest patriotism to the service of America." Charges of disloyalty against Marshall, the paragraph concluded, constituted "a sobering lesson in the way freedom must not defend itself."

Someone at headquarters - it was never discovered who - told the Wisconsin Republicans of Eisenhower's intentions. On October 2, while Eisenhower's train was in Peoria, Illinois, for an overnight stop before heading north to Wisconsin, the Wisconsin governor, Walter Kohler, the national committeeman, Henry Ringling, and the junior senator, Joe McCarthy flew by private plane to Peoria to confront the general... He [Eisenhower] said he would meet with McCarthy alone... The private meeting lasted a half hour. According to Kevin McCann, recalling the event years later, "[Eisenhower] just took McCarthy apart. I never heard the General so cold-bloodedly skin a man. The air turned blue - so blue in fact that I couldn't sit there listening, McCarthy said damned little. He just grunted and groaned... He was no heavyweight anyway. And under attack he just went into shock."....

The next day on the train they all reviewed the draft of the speech, and Ambrose has it going like this:

Kohler told Adams he liked the speech, but wanted the Marshall paragraph removed, as it was unnecessarily insulting to McCarthy in his home state. He suggested that Eisenhower could defend Marshall somewhere else. At this point it becomes impossible to determine who said what to whom. By some accounts, Adams agreed with Kohler; by others, he was strongly opposed to removing the paragraph. Supposedly Hauge and Boston banker Robert Cutler, a member of Eisenhower's staff and a wartime aid to Marshall, were adamant about retaining the remarks. The general himself, according to some of those present, insisted upon keeping it; others could not recall his participating in the conversation. In his memoirs, Eisenhower was extremely vague about the whole thing, saying only that he told McCarthy, sometime during the train ride, that he intended to speak out against McCarthy's methods in Green Bay. McCarthy replied, "If you say that, they will boo you." Eisenhower responded "with some heat" that he had been criticized before for his actions, and that it did not bother him, and that he would "gladly be booed for standing for my own conceptions of justice."

Whatever happened, Ike didn't read the paragraph in Green Bay, and Ambrose has the discussion continuing on the train afterwards:

As the train moved toward Milwaukee, the argument over the Marshall paragraph continued. Kohler told Adams that he felt it stood out as an "unnecessarily abrupt rebuff to McCarthy" and said that it would cause serious problems for the Republicans in Wisconsin in the election (Wisconsin had gone Democratic in 1948). Eisenhower had already defended Marshall in Denver, Kohler argued, and he also insisted that it was Jenner, not McCarthy, who had called Marshall a traitor.

Adams then went to the rear of the train to argue Kohler's case with Eisenhower. "Are you suggesting that the reference to George Marshall be dropped from the speech tonight?" Eisenhower asked. Adams responded, "Yes, not because you're not right, but because you're out of context." The general then said, "Well, drop it. I handled the subject pretty thoroughly in Denver and there's no reason to repeat it tonight." Hauge and Cutler protested, but to no avail.

So, to answer your question, Eisenhower doesn't seem to be that bad of a friend. He just appears to have adapted his wartime diplomatic role to politics to keep his party together.