Pearson vs. Catalina
I have a strong bias towards Pearsons, so know that going in. I currently own a P-33-2 for one. You''ll get opinions all over the place about Pearson quality vs. that of Catalina. While I admire the job Frank Butler does at Catalina (he knows his customer base and builds boats accordingly, and his owners are as loyal as they come), I personally would stick with Pearson. I''m not sure of your location so can''t vouch for availability, but I can suggest either the Pearson 34 or 34-2 as logical move-ups from your 323.
As for performance, PHRF ratings are one way to compare boats (although not foolproof.) Here are the PHRF ratings for these models. Source is either www.phrfne.org, or www.pearsoninfo.net. Note that both the P-34 and C-34 models changed during the production run. Catalina in particular "freshens" designs through the years, thus the ability to build 2,000+ hulls of some models.
C-34 Tall Mast 150-165