Neoseeker has published a review and overclocking comparison of the AM2 65nm 5000+ vs the previous 90nm 5000+ and also against the similarly priced E4300 and E6300/6400 Core 2 Duo chips

I managed to get it running with FSB speeds as high as 345MHz - but only with significantly reduced multipliers. In order to get the best possible balanced score, I spent a lot of time trying different multiplier and FSB combinations, and frankly my experiments were made needlessly frustrating by the unpredictable ways it would choose the memory speed dividers.

65nm 5000+ AM2 Review