Lynnfield's IMC was complete garbage so yes a lot less.
Heck no. It's not that far behind a Bloomfield in bandwidth, and it's actually better in some latency measurements, depending heavily on the memory used of course. It's also a hair better than K10.5 in latency, and significantly better than K10.5 in bandwidth. I would be very surprised if you could find more than a tiny handful of programs that would be even close to memory limited on a Lynnfield.