"I wouldn't be too negative on high-yield bonds compared to the stocks," he said. "Stocks need to be supported by strong profit numbers. The income statement needs to be strong. Bonds need to be supported by a strong balance sheet," Idris noted. "Right now, most corporates have strong balance sheets, but weak income statements," indicating bonds have more fundamental support.
To be sure, there are some concerns about the sector's outlook.
Read MoreWill yields on high-yield bonds get even lower?
"The next trick for her would be to keep markets stable when she decides to normalize interest rates. That would be the tougher one," Idris said.
Kapstream's Goldman agreed.
"When they start talking about hiking rates, markets will start moving out of risky assets," Goldman said. "You've now created another risk to stability."
While Idris isn't as concerned about high-yield bonds' fundamentals, Goldman has noted a deterioration in underwriting criteria.
The average covenant quality for high-yield bond deals in North America has slipped below the global average, according to data from a Moody's note Tuesday. North American deals are scoring an average 3.55, compared with the global average 3.33 and China's average of 2.57, the data show; higher scores indicate lower quality.
Others see some reasons for concern over junk bonds. Bank of America-Merrill Lynch's survey of fund managers for July found U.S. high-yield debt is considered the most crowded trade.
"Security selection will be more critical than in the past," Goldman said. "A lot of dogs are coming out now."
—By CNBC.Com's Leslie Shaffer; Follow her on Twitter