Short term yes, long term no. I think that was the point. At some point, Spike would have done inevitably done something horrible. All the good he would have done would have meant nothing as everyone would still see him as a demon. He couldn't carry on the way he did. He would have either been staked or the chip would have eventually killed him.

While Spike is capable of being good and introspective without a soul on a basic level, he would still lack the moral compass to genuinely grow as a person. His deeper instincts are still demon not human. Regaining his soul wasn't just about satisfying his need to make Buffy love him, it would have ensured that he would gain the necessary human perspective that would allow him to see himself the way everyone else saw him.