The pressure and flow, will be a result or sum of all the pressure losses.
So if you have four sections of pipe, Section A, B, C, D
The loss will be the sum of those, If you replace a section of 3/4" line with 1" line then the resultant loss will be lower and you will have slightly better water flow and pressure.
But to be honest 25 feet of straight line won't make much difference.
If you are going to have to use an adaptor then make it at the meter. Can't hurt.