I bought a .243 for my wife a few years back with one of those "horrid" Simmons 8-point 3-9x32's mounted on it. I always said I would replace it whenever I noticed it wasn't holding zero or some other problem arose. Well, I'm still waiting for it to fail. So I won't knock your scope choice if that's what you want.
I have pretty much the same rifle as you, a Howa 1500 in .25-06. I've got a two piece Weaver base and steel Weaver low rings holding a Burris FFII 3-9x40. The good ole cheap Weaver stuff has never let me down, so I continue to proudly use them, even if they are sold at Wal-Mart
As for 40 vs 50mm scopes, I have never noticed enough of a difference in brightness in low light conditions to see the advantage of a 50mm, and higher rings must be used with a 50mm, so that's another reason IMO to use a 40mm. You get a little larger field of view with a 50 but I never thought it to be worth it. But everybody has their preferences. Use what you like and don't worry about what the $1000+ scope crowd says.
Well after a couple deals fell through for cheaper scopes at cut throat prices, I petitioned for an increase in budget. The treasurer gladly approved a higher tier of optics. Sooo, now I'm debating and shopping between a Sightron SI Hunter 3-9x40, Nikon Prostaff 3-9x40 with nikoplex reticle, Vortex Crossfire II 3-9x40/50 and a used Burris Full field II 3-9x40. Any insight into any of these models would be great, especially if you currently own one or have owned one.