I have owned in Newton for years and find it ok. Avoid anything south of 119 Avenue, as all the action occurs on 118 ave. 3 bedroom house rents for $1500-1600. I bought the property after the old owner cleaned up after their's third bad tenant, and wanted out.
On 118 ave, you get decent rent, but expect double the turn over and higher collection costs.
If you go north to 155 ave and 110 st, Lorelei, (castledowns district) you get 1700-1900 rent. Better properties, for about $50 to 75K more. Better tenant profile.
But your realtor should have the answers for you.