I've done IMLP twice-2012 (last of the mass swim starts) and 2016 (rolling swim start).
S-What can you say about the nicest swim in IM. Enjoy it. Rolling start but know that people do not seed appropriately so choose a slightly faster time. I swear Mirror Lake turns into a slowly turning whirlpool. Water is crystal clear with absolutely no muck/seaweed. Bring bonus shoes/sandals or something to walk around in before as there is a lot of walking-especially if you drop bags at special needs.
B-As with all IM races, keep to your power plan early and know that the technical portion is just getting out of transition and there is some uphill early leaving town (*esp mile 4). The course is pretty and scenic. The change is now back to the 2012 course and doesn't really impact the overall plan at all. You will be leapfrogging the slower cyclists on the second loop, no doubt. The bears are steady inclines and not bad at all.
Exit transition with a 180 degree turn left and then 90 degree turn right. 2 Loop course heading out of town up a slight hill followed by several miles of short rollers. These rollers are not insignificant and mile 4 is a real hill which took me 6 minutes at 185 watts. Do not burn matches you do not need to. The Keene descent is actually a long, winding switchback road so even though you get to 50mph, there are sections of it. The third is the most twisting and has some areas of road that are still a quite bumpy. I was extremely fortunate to have low wind for my pair of 808's as this can be very dicey with crosswinds and worse with wet conditions. After this, there are 30 miles where you can push a steady pace. After experiencing the easy part, the second half will tax you if you went out too hard. I did not think anything about the Bears the first time around, but they got bigger by the second loop. https://connect.garmin.com/...ctivity/1271236804/2
and my strava https://www.strava.com/...52526145#15968339942
R-A bit hilly but LOTS of support. Hold back early as the first 2-3 miles is net down 150 ft, then flat for 5-6 miles before the hills (which are only ~200ft total in two steps)
Slightly down for the first 3 miles followed by flat, small rollers for 3 miles, The first hill starts at mile 9 and is only ~75 feet. There are then a series of pretty short hills that are much higher on the second lap also. Getting back up the hills in town are much more challenging at the end and you appreciate how steep they are. It hurts to have to run past the Olympic stadium going into the second lap. Torture to have to run past it again and do an out/n/back before actually finishing after completing the second lap. Finishing in the stadium-priceless. https://connect.garmin.com/.../activity/1271236860
I do love the course personally. Be prepared for a possible 25-30 degree increase from start to finish.
Hopefully I will see you at Quassy and we can talk more, if you have any questions that I can help with.