Custom 1.75" catback exhaust - worth it??

[fuji]

I had a 2" custom exhaust installed not to long ago. I was hoping to see a bit more oomph in the mid to upper ranges but the results have been slightly diappointing. I definately noticed the lack of oomph in the lower end.

I know most people would install a 2" or 2.25" piped exhaust but is there a way to constuct a free-er flowing 1.75" that would restore the lower end oomph while giving some benefit up high as well?

Any difference in power when adding resonators and high flow catalytic converters? Just better not to run a resonator???