Experimental Catagory: Pros and Cons?

The difference is whether your glider import and/or initial
airworthiness in the experimental/racing category was pre-(July 9,
1993) or post-(August 18, 1993) moratorium. See FAA Order 8130F with
latest change. Gliders are in Group I. All relevant paragraphs of the
order for the group apply to post-moratorium gliders. Post moratorium
gliders, regardless of country of construction, will have operating
limitations under this order.

Regarding the annual program letter, from paragraph 37:
(37) The owner/operator of this aircraft must submit an annual program
letter update to the
local FSDO that lists airshows, fly-ins, etc., that will be attended
during the next year, commencing at
the time this aircraft is released into phase II operation. This list
of events may be amended, as
applicable, by letter or fax to the FSDO prior to the intended
operation amendments. A copy of the
highlighted aeronautical chart, when applicable, must be carried aboard
this aircraft and be available to
the pilot.
(Applicability: All)

If it's included in the operating limitations, it's required. You
won't find this statement in pre-moratorium operating limitations.
Keep them safe and dry.

The operating limitations are part of your special airworthiness
certificate, FAA Form 8130-7. Pre-moratorium gliders have a seemingly
permanent and portable set of operating limitations. Post-moratorium
gliders airworthiness certificate does not expire, however, there are
30 day reporting requirements regarding change of address of the
registrant or for change of owner or base of operations. Since there
may be a new program letter requirement (the program letter is just a
required extension to the OL's) due to any of the above. A change of
base of operations will require a change in the operating limitations.

Frank Whiteley