Yep, those are the sites I was just going to post but you beat me to it. In fact, I had already posted them 2 or 3 times on this site. The larger filter is the PF52. I believe the factory filter is a PF47. Those of course are GM part numbers, but to make it easier, the PF52 was used on the LQ1 equipped cars (among others), such as the 1992 Chevy Lumina Z34 with the 3.4L V6. It fits in both my regals. The advantage is that it has more filter media, so it goes longer before it gets clogged. Once your filter gets clogged, the bypass valve opens and you're not filtering anything. It also allows you to flow more oil at higher pressures before the oil goes through the bypass, such as with hard, high-rpm driving. Plus, they cost the same. I haven't yet found a single reason *not* to use one, unless it simply doesn't fit, which at least with my 2000 Regal and my 1995 Regal is not the case.
I'd recommend a purolator, wix, or mobile 1 filter. The above links also rate the wix filters well. Mobile 1 filters are a tad expensive.
2005 Pontiac Bonneville GXP - For Sale ----- 1995 Buick Regal GS(X) - L67 madness
2000 Buick Regal GSE - Stock...for now
----- 1987 Jaguar XJ-* V12 - 12>8