I'm looking at getting a new wheelset. Formula hubs with either 28-hole Velocity arrowhead rims, or 32-hole Velocity fusion rims. Do the extra spokes add that much more strength? I only weigh about 185, but commute and carry a lot of weight with me sometimes. I also will be riding on a lot of hills on non-commute days so weight is sort of a concern. The Fusion rims look like a good medium point between the arrowheads and the deep v's. Any opinions? (by the way, the 28-hole arrowheads are 15 bucks cheaper)

for bombproof- go 36. I think its worth it for commuting and the fact that you are a borderline-big guy.

Really if you're commuting, go with the higher spoke count.

On non-commute days you really won't notice the difference. I pretty much always ride with 32 3cross wheels and used to ride plenty of hills (in and around SF) with no probs. Lots of longer rides etc.

Haven't seen the fusion rims so whether thats a good rim or not, I'll leave for others.

do formula hubs even gome in 28 hole?

get at least 32 for your size.

what is a big-guy. I am 6 foot and 165lb. i run 32 hole on street all day.

yea, in my personal opinion, I don't see the need to run 36 hole.
Reason, being is that its ugly and unsymetrical.
However, 32 hole is pretty because it is symetrical

*edit* - I just re-read your original post and yea, it seems that you should run more on the 36h side
nothing personal though.

32h is the, um, jam? Yeah. Nice middle ground between 36 and 28. Plus you have the widest range of rims to choose from.

Go with 32.

I've got two sets of wheels built with 32 hole Velocity fusions, both laced 3x- one built up on Promax the other on Surly. I've used them all year round and for commuting, and not a problem so far. They're nothing uber-fancy, but a nice blend of weight, durability, and value. Dunno if it makes a difference to you, but at least at the time I got mine, the Fusions only came in black, but in today's fashion forward world, that may have changed.

I don't think a "big guy" make much of a difference, I happen to run Formula 28holes, and I'm 200lbs, 225 with the crap I have to carry (lock, books, etc.). Bike rolls like a dream even on the atrocious roads we have in chicago...

actually it makes a huge difference in the life of the wheel. IMHO, there's no reason someone our size who's not racing should be riding around on less than 32's (and only then if it's an even-dished wheel.) When doing custom builds for folks over 150# I won't guarantee the build if it's less than 32 spokes.

The aerohead is pretty damn light (QBP lists 405 grams) for someone your size. The thing to remeber about bicycle components is that they were designed for 140 lb racers who are (while stronger) are often much smoother than most of us. They ride frequently replaced bikes on smooth tracks or good roads. When they deal with crappy roads (Paris Roubaix, Flanders) you will see racers running 28c tubulars on 36 hole box section rims.
The additional weight of 8 spokes and nipples is negligible for non-racers and high spoke count wheels are stronger and easier to maintain (ever try taking a flat spot out of a vector pro?) One of the few justifications for folks to run low spoke count wheels is aerodynamics. Roadies pounding along in 53-12 can hit some very high speeds and the additional drag of a 36 spoke wheels really matters. In urban settings with low-ish street gearing much of my riding takes place between 15-25 mph where aerodynamics are not as important. If you are obsessed with weight, buy 14/15 spokes and run a 28 or 32 hole wheel up front, but at 185+ cargo, I would recomend a 36 hole Ma3, cr18, open pro, or fusion for the back.