Okay - so I'm going to disagree with the others just slightly. While it is true that Slinky G+ goes first - that also means you're likely to get a much later time in the day for your LL (let's say you get lucky and get a 1pm LL for Slinky)
One of the strategies to getting the most out of G+ is to try to overcome the '2 hour window' and roll your LLs if at all possible. So if you get a 1pm LL for Slinky - you won't be able to make another LL selection until 11am (if the park officially opens at 9am). Whereas if you can get a LL for MMRR for 9:40am - you can make another LL for a different ride after you tap into MMRR at 9:40 (a whole hour and 20 minutes earlier). Does that make sense?? So you could make a LL for Star Tours or MF at 9:40 instead of 11 am. (and the return times for your next LL would be better/ earlier at 9:40 rather than at 11)
It's a strategy best used at MK - you can literally keep rolling LL and moving onto the next LL reservation after you tap in. At some point during the day, the window for every ride stops being shorter than 2 hours and you just have to wait it out between LL reservations, but this was how I got the most use out of G+ in the mornings.
This strategy will be limited a DHS, but I would rope drop Slinky and grab a LL for MMRR if I were you. (Unless something has changed and MMRR goes as fast as Slinky these days)