Yeah, that's why I wouldn't listen to the guy at a T3/T4 who couldn't get interviews with biglaw.
1L summer employment isn't NECESSARY to get a job, but good 1L summer employment is certainly helpful...
1L employment isn't NECESSARY to get a job (assuming you are taking "employment" to mean a 1L firm job -- you need to do SOMETHING your 1L summer) -- but those with 1L firm jobs usually have great grades, strong resumes, soft factors, and interview skills that help them with the 2L job search as well. A friend took an unpaid public interest 1L job but is on law review and will be working at a V10 her 2L summer so again, a 1L firm job isn't necessary.
Basically as a 1L you want something interesting to talk about during 2L interviews. Some of my classmates went abroad and took classes (got 6 credits to transfer) which sounded pretty cool and lightens your courseload. A 1L firm job can be a good or bad thing. It was nice to have a return offer, but it made me slack off during interview season (I only applied to a handful of other firms because I liked my 1L firm). It's a lot less stressful, but you might be limiting your options.
For 1L summer, do whatever you prefer. It shouldn't make a huge difference which you choose.