This is a "definition" type theme with no revealing entry or unifier. All of the theme clues are types of berries, but the answers are not.
17-Across. RASPBERRY : SOUND OF DERISION. Here's a quick lesson on how to get it just right. 1:49
26-Across. BLACKBERRY : WIRELESS DEVICE. And we also have 11-Across. 26-Across download : APP.
43-Across. HUCKLEBERRY : TWAIN CHARACTER. The inimitable Finn.
56-Across. STRAWBERRY : REDDISH SKIN MARK. Also known as a "hemangioma," they usually appear at birth and often fade with time.
Two fifteens and two fourteens allow for some freedom in the fill. Some nice long down entries with A BIT SIMPLE and Dracula's WIDOW'S PEAK. Other nice shorter entries made this a pleasant diversion from the trials and tribulations of life...
1. "Find your own road" automaker : SAAB.
5. Bitter disagreement : STRIFE. If it escalates, it might become armed.
14. Minuscule lake plant : ALGA.
15. Wee hr. : FOUR AM. One or two AM? - too short. Three AM? - too long. FOUR AM - juuuust right!
16. Dude : BRO.
20. Vampire's bane : STAKE.
21. T-man, e.g. : FED.
22. Courageous : GUTSY.
23. Hermey of TV's "Rudolph the Red-Nosed Reindeer," e.g. : ELF. He wanted to be a dentist.
25. Take out : ERASE.
32. Newtonian elements? : FIGS. Fun misdirection. They now have STRAWBERRY and Triple BERRY Newtons, but I still like the Fig Newtons best.
33. Is ready for business : OPENS.
34. Big runners : EMUS. Early week puzzles would have some kind of reference to "down under."
35. Bustle : ADO.
36. Natural resource : ORE.
37. Educational org. : PTA.
38. Chloé fragrance maker : COTY.
Imogen Poots - one of the faces of Chloé
40. Good-sized chamber ensemble : OCTET.
42. Baseball family name : ALOU. Even I, baseball-challenged as I am, remembered this family.
46. Goal line play : SNEAK. The quarterback sneak. The ball is snapped as usual, but instead of passing it off to another player, the QB himself dives for the goal line. Usually done on 4th down and short yardage. Bart Starr used one to win the game in the 1967 NFL Championship.
47. Kitchen tool : POT.
48. Like wasted milk in Westminster : SPILT. American English spells spilt "spilled."
49. Its HQ is named for George Bush : CIA. The George Bush Center for Intelligence.
52. Schisms and chasms : RIFTS.
59. __ kwon do : TAE.
60. Sherlock Holmes' instrument : VIOLIN.
61. Small case : ETUI.
62. Wanted-poster letters : AKA. Also Known As...
63. Use : EXPEND.
64. Percolate : SEEP.
1. Fresh answers, say : SASS. Nice misdirection.
2. Oodles : A LOT.
3. Lago contents : AGUA. Spanish lago = lake, agua = water.
4. Ones showing varying amounts of interest? : BANKERS.
5. Facility about 350 miles NW of LAX : SFO. San Francisco International Airport.
6. Beau Brummel, for one : TOFF. Derogatory British word for an aristocrat.
7. Brusque : RUDE.
8. Steamed : IRED.
9. Word with cry or out : FAR.
10. Future citizen, perhaps : EMIGRÉ. C.C. was an emigré from China, and got her U.S. citizenship on June 2nd, 2010.
11. Not particularly challenging : A BIT SIMPLE.
12. "Law & Order" figure : PROSECUTOR.
13. County fair mount : PONY.
18. Mark of rejection : DELE. Editor's rejection, that is.
19. Like James Bond : SUAVE.
24. Ubiquitous insurance spokeswoman : FLO. She annoys me.
25. To whom reporters report: Abbr. : EDs. Editors, who sometimes reject their entire story...
26. Dracula feature : WIDOW'S PEAK. Nice fill.
27. Brainstorming cry : I GOT AN IDEA. Nit: Technically, "got" is the past tense. You might say, "While we were brainstorming yesterday, I got an idea." But during the actual session, you should cry "I have an idea!" You could even use colloquial English and say "I've got an idea!" But I GOT is just poor English. Unless you're Spike Lee, and then you can say "He Got Game!"
28. Historical segment : EPOCH.
29. Simmons competitor : SERTA. Sealy also fit. Just sayin'...
30. Show contempt : SNEER.
31. Son of Isaac : ESAU.
32. Fundamental of science : FACT.
39. Harvest output : YIELD.
40. Spider-Man nemesis Doc __ : OCK.
41. Select : TAP. You can tap a friend for a loan. In that case, you probably should select one who is both generous and rich.
42. Occasionally : AT TIMES.
44. From around here : NATIVE.
45. Podiatrist's concern : CORN.
48. Mlle., in Monterrey : SRTA. Abbrs. for mademoiselle and señorita.
49. Recipe verb : CHOP.
50. Cruise destination : ISLE.
51. Related : AKIN.
53. You've got it coming : FATE. Do you believe in FATE? 54-Down. "No argument here" : TRUE.
55. Ignore : SKIP.
57. Pack quantity : SIX. Six pack. Beer or abs.
58. Senator Sanders of Vt., on ballots : IND.ependent.
So now I'll take my leave, and see you next Thursday!