How big is too big??

Yesterday I had a surprise visit from my FIL and BIL.  They were in the neighborhood dropping off a mower to be repaired and wanted to swing by and pick up some equipment that the had loaned us.  My FIL is an avid gardener, and works at a local restaurant that specializes in serving locally grown food.  A great place to eat with a friendly laid back environment.  And my FIL has learned a lot from his involvement there...and off handedly told me my asparagus was much too big.  He said that the restaurants want the thin spears (the ones off the smallest plants or late in the season).  I told him no, I don't think so.  Why would you stop harvesting at that very stage?  I told him it was unhealthy for my plants to harvest the tiny "newbie" spears, that that weakens the crown.  And that the largest ones are in fact quite tasty, and not at all woody.
But at the same time I became perplexed.  Here he is, working with a fine gourmet chef, and I believe he knows what they say they want and need in the kitchen.  No doubt I trust his judgement.  But why then, do the plant breeders emphasize the size of the spear?  My particular variety, I read, can get up to 4 cm in diameter, on the healthiest spears.  And other similar varieties are named for their size and girth...IE Jersey GIANT.  Why then would the chef's think that they are inedible?  I don't understand this at all.

I have been thinking how beautiful and creamy colored the spears are when they begin to push through the surface...and thought about blanching a few spears for experiment's sake....then he could see how very tender the spears can be.  I just don't know that is true of it.  What I know of Asparagus, you do NOT harvest pencil sized spears, because it marks the end of the harvest.  And that it is common, or preferred to have spears the size of a grown man's thumb.
So...I must do the only thing I know how....GOOGLE IT!!!  :)

Here is what I've found:

This is from a PDF from Texas A&M University:

"Harvesting
Harvest asparagus spears from established
beds for about 8 weeks, depending
on the area. Do not harvest during the first
2 years after planting. This waiting period
enables the underground crown to grow
and store enough reserves for a strong harvest
for many years to come.
Harvest the spears when they are 4 to
10 inches long. To prevent the spears from
becoming fibrous, harvest at least every
other day. The fibrous condition is caused
by overmaturity or inadequate fertility.
Spears with loose or opened heads are too
mature.
To harvest, snap off the spears by
hand at ground level. Never snap asparagus
spears above the ground or allow a
stub to remain. An alternative method is to use a
knife to cut the spears 1 to 2 inches below
the soil level (Fig. 4). To avoid damage to
the developing buds in the crown, never
cut the spear too deep. However, this
method is not recommended because the
knife may spread diseases from crown to
crown.

Stop harvesting when the spear diameter
becomes less than 3⁄8 inch or when the
spear heads open up with rising temperatures."

And even better, because it verifies my belief, from Illinois;

"While Europeans prize white asparagus, Americans tend to prefer the green or violet-green varieties. When buying asparagus look for compact tips and smooth green stems that are uniform in color down the length of the stem. Check the cut stem end for any signs of drying and always avoid withered spears.
Pencil thin or thick stems can be equally delicious. Contrary to popular belief, thinner stems are not an indication of tenderness. Thick stems are already thick when they poke their heads out of the soil and thin stems do not get thicker with age. Tenderness is related to maturity and freshness.
Asparagus comes in a variety of colors including white, violet-green, pink and purple. If you must store any variety of asparagus, treat it as you would treat a cut flower. Trim the stems and stand them in a glass with one to two inches of water. Cover with a plastic bag and refrigerate for 2 to 3 days or until ready to use."

This is even more helpful to Missouri growers, because of the proximity to our state and similarity of climate. As far as I know, bigger is better...this is not a zucchini or a cucumber, where maturity means the seeds are ready to reproduce, and sacrifice flavor for it's growth...this is altogether a different entity. 
Here is another excerpt from Ohio;

"Buds on an asparagus crown are arranged in a "dominant hierarchy" or "pecking order" system. The first bud to emerge as a spear is the largest in diameter. When a spear from a crown is harvested, it signals another bud on that crown to send up another spear. With each successive spear that is harvested, the spear diameter decreases because the lower-order buds are smaller and produce smaller diameter spears. The largest spears occur between the second and fifth week of harvest and decrease rapidly thereafter. This is why asparagus harvesting should stop after a certain number of weeks to allow the crown to send up small diameter spears that will lignify and become ferns to manufacture carbohydrates to send down to the crowns for next year's crop. Spear diameter during the first year after crown planting will be smaller and possibly more difficult to market than the larger spears produced after the first harvest season.
Because the length of harvest season will vary from year to year depending on air temperature, stopping the harvest when one-fourth to three-fourths of the spears have a diameter of less than 3/8 inch (about the diameter of a pencil) is a better guide than harvesting for a specified number of weeks. Experienced gained by growing the crop will make it easier for the grower to know when to discontinue the harvest. Over-harvesting will weaken the crown, reducing the amount of carbohydrates stored for the following year, and will lead to further decline of the planting, putting plants under stress and making them more susceptible to insects and diseases."

And here is a brief (ha ha, to me brief!) list of links:
Asparagus yields

Kentucky U Asparagus bulletin

Maryland U

enchantedspoon.blogspot.com

www.marketmanila.com

how stuff works

www.vegetablegardener.com

I think I am satisfied with the answers, but if anyone has personal experience with growing Giant Asparagus, please feel free to comment.  But, in the meanwhile, I like that mine are humongous and will enjoy them thoroughly.  In fact, while googling the answer to this quandary, I found several suggestions for preparing the Asparagus, including bacon wrapped grilled ....mmmmm, yum!  Everything tastes better with bacon!!
Catcha later!  :)