Anyone have any experiance with these carbs? How well do they work on mildly built 350-383 street/daily driver small blocks?

 

It should work fine on a 350,a 383 depending on the build might like a little more carb though.
I had a Holley 650 spreadbore double pumper with manual secondaries and a manual choke on a mostly stock 396 once,that was a real nice set up.
Performance wise I'll take manual secondaries and a double pumper any day over that vacuum secondary single pump carb.

Here it is.
http://www.holley.com/0-4777S.asp

 

I'm definitely going with vacuum secondary. I had a Holley 750 double pumper on my last '78 Camaro.

It worked great on that car. It had a 406, 10.5:1 compression, Dart Sportsman II heads, small solid Crane cam 244/252 dur. @.050" .518/.536 lift 106° LSA, Team G intake, TH350 with a 3800 stall converter, 4.10 gears. It went 12.70 at 106 mph on street tires through a full length exhaust. It would have gone a lot faster if I could have gotten it to hook better, my 60 foot times were right around 2 seconds.

This car is going to be a baby. I'm going to drive it everyday. I was going to build a 383, now I'm not sure if I'm going to build a 355 or a 383 for it. I'm on an extreme budget and I'm not looking for a racing car. A 355 might work out better for me.

I think whether I go with a 355 or a 383 I'm going to go with a set of World Products S/R Torquer Heads 2.02/1.60 valves 67cc chambers, Forged pistons 9.3:1 compression, Comp Cams CSXE 268H-10 hydraulic flat tappet cam 224/230 dur @.050" .477/.480 lift 110° LSA 1600-5800 rpm range. Performer RPM intake (square flange or spread bore depending on carb). 1 5/8" full length headers 2 1/2" full length Flowmaster exhaust system. 2200 stall converter max with 3.42 gears.

I'm looking for a Holley carb that with work well and be very good as a daily driver. I'm willing to give up a little power to gain derivability. I also looked at the 80670 and 80783C carbs.

 

Well the 650 spreadbore double pumper is a lot different than the 750 even bore double pumper,it's still a 650 spreadbore with the smaller primaries so if you keep your foot out of it you should get about the same mileage as the single pump vac secondary carb but when you do stomp on it she'll have a lot more kick.
I sure liked the one I had on the 396.
Sounds to me like the 355 would be the way to go for you,less money and still plenty of giddyup.
If you do go 383 I think it would be a waste of money with that carb,it would need a little more IMHO to get to its' real potential but it would run and it would be torquey,just not the bang for the buck you'd get out of a 355 and that carb.
Just my 2cts.