My favorite time to play control is when control is bad.
Perhaps it's slightly more accurate is to say that my favorite time to play control is when people think control is bad.
What I mean is, the control mirror arms race is a nightmare. Once people are sideboarding a million Stratus Dancers and Risen Executioners in order to beat each other, control begins to lose the strength that it once had against the rest of the field. However, when there are just a small handful of matchups that you know to gear your deck for, control decks are among the best choices. This is the perfect time to play control!
This is the deck I played in Grand Prix San Diego. At one point I had a 10-1 record, but things went downhill after that. I got an unintentional draw in round 12, three cards short of milling my opponent out with both an Ashiok, Nightmare Weaver and an emblem from Jace, Telepath Unbound. Then I lost my last three matches for a fine but unsatisfying 61st-place finish.
Devoted readers might remember that I also played U/B Control at Pro Tour Magic Origins the previous weekend. After the dominant performance of Mono-Red, I decided to move my Jace, Vryn's Prodigies to the sideboard so I didn't get Searing Blooded into oblivion. I geared my deck incredibly hard toward beating Mono-Red, and it paid off, as I beat red aggro 2-0 in matches and 4-0 in games. Mono-Red need not be a bad matchup for UB Control, but you do need to put in the effort.
I made major changes to my mana base in order to accommodate Radiant Fountains, as they're incredibly important against people that want to burn you out with Exquisite Firecrafts and Shrapnel Blasts. However, I would frequently sideboard out a land (down to 26), as that's a comfortable number for a lower-curve control deck like this, and you don't want to flood out in slower matchups.
I noticed myself winning a lot more with control once I gave up my sacred cow—Ugin, the Spirit Dragon. It's just better to stay low to the ground in Standard right now. The fast decks can kill you before you hit 8 mana. Green Devotion can trump Ugin with Gaea's Revenge. Thoughtseize decks get ample time to strip it from your hand if they feel the need to do so. Perhaps most importantly, abandoning your 8-drops allows you to loot away excess lands with Jace, and gives you the freedom to choose nonland cards off of your Dig Through Times.
All in all, I'm very happy playing UB Control in Standard right now. I was also fairly happy with my deck list for the Grand Prix, although it certainly wasn't perfect. Unless there's a resurgence of Mono-Red, you can probably sacrifice a bit of the early defense for some more late-game power (like another Dissolve, card-drawing spell, or something like a Prognostic Sphinx).
If you want to beat up on Abzan Control and Green Devotion, this might be the deck for you. Also, stay tuned for more updates, as I'll definitely be working more on UB Control over the coming weeks.