The new one has the scale/ruler as well. Yes, it matters. I used the old one for about 4 months, but it just stank. Now, it sits in a drawer. I tried selling it, but no one would buy it. I really think the new one is improved, and it appears that many agree. I rarely see the new Wave sell for less than $50, new or used('cept for mine on ebay), but haven't seen the old ones sell for over $25. That does not represent the entire market, but seems to show a considerable lack of demand for the older tool.