My dealer said that they put a few of the new Shindaiwa 8510's out in service now and have had complaints that they use a ton of gas..much more than the 630 or the Echo PB-751's that he sells. The 8510 is much heavier as well...don't believe me...try one on!
This is info from the field from landscapers and I found it very interesting especially with gas prices hovering around $3.00 a gallon. BTW..they sell for $549.99 less a $50 mail in rebate.
I'm sticking with the Echo PB-751's...very good power, decent weight and relatively quiet....not a major gas hog either!