The old CD HOT ROCKS compilation is labeled as "Remastered," and the recent compilation 40 Licks is obviously remastered with today's technology.

Which comp sounds the best? or are they equal?

40 Licks, without any competition.

Careful though, 40 Licks edited some songs so that they could fit 40 tracks on two CDs.

They both sound good but the big difference between HOT ROCKS is old Stones from 1964-71 and 40 LICKS is 40 years of STONES on 2 discs. These 5 are on HOT ROCKS but not on 40 LICKS: Time Is On My Side, Heart Of Stone, Play With Fire, As Tears Go By, Midnight Rambler (Live) . All the ones in bold are only on 40 LICKS. Below is the track list for 40 LICKS.

Disc: 1
1. Street Fighting Man
2. Gimme Shelter
3. (I Can't Get No) Satisfaction
4. The Last Time
5. Jumpin Jack Flash
6. You Can't Always Get What you Want
7. 19th Nervous Breakdown
8. Under My Thumb
9. Not Fade Away
10. Have You Seen Your Mother, Baby
11. Sympathy For The Devil
12. Mother's Little Helper
13. She's a Rainbow
14. Get Off My Cloud
15. Wild Horses
16. Ruby Tuesday
17. Paint It Black
18. Honky Tonk Women
19. It's All Over Now
20. Let's Spend The Night Together
Disc: 2
1. Start Me Up
2. Brown Sugar
3. Miss You
4. Beast Of Burden
5. Don't Stop (new)
6. Happy
7. Angie
8. You Got Me Rocking
9. Shattered
10. Fool To Cry
11. Love Is Strong
12. Mixed Emotions
13. Keys To Your Love (new)
14. Anybody Seen My Baby?
15. Stealing My Heart (new)
16. Tumbling Dice
17. Undercover of the Night
18. Emotional Rescue
19. Only Rock 'n Roll (But I Like It)
20. Losing My Touch (new)
Myself I have both 40 LICKS and Singles Collection: The London Years and love them both.

Speaking of comps, STONES just put out another one Rolled Gold +: The Best Of The Rolling Stones.

Track Listing for Rolled Gold +
Disc 1
1. Come On
2. I Wanna Be Your Man
3. Not Fade Away
4. Carol
5. Tell Me
6. It's All Over Now
7. Little Red Rooster
8. Heart of Stone
9. Time Is On My Side
10. The Last Time
11. Play With Fire
12. (I Can't Get No) Satisfaction
13. Get Off Of My Cloud
14. I'm Free
15. As Tears Go By
16. Lady Jane
17. Paint It Black
18. Mothers Little Helper
19. 19th Nervous Breakdown
20. Under My Thumb
21. Out Of Time
22. Yesterday's Papers
23. Let's Spend The Night Together
24. Have You Seen Your Mother, Baby, Standing In The Shadow?

Disc 2
1. Ruby Tuesday
2. Dandelion
3. She's A Rainbow
4. We Love You
5. 2000 Light Years From Home
6. Jumpin' Jack Flash
7. Street Fighting Man
8. Sympathy For The Devil
9. No Expectations
10. Let It Bleed
11. Midnight Rambler
12. Gimme Shelter
13. You Can't Always Get What You Want
14. Brown Sugar
15. Honky Tonk Women
16. Wild Horses

Hot Rocks has some additional songs, like Play With Fire, which is a great tune.

Indeed it is, and it was recently used to great effect in The Darjeeling Limited and on that film's soundtrack.

Isn't the latest remaster of Hot Rocks one of those dual layer SACD where one layer is your regular CD and the other layer a SACD player?

I'm not really concerned about the content. I'm just wondering that, since "Hot Rocks" was remastered, if it sounds as good (if not better) than "40 Licks."

I listened to 40 Licks a few times, before buying the remastered Hot Rocks, and I personally think Hot Rocks sounds a tad better.