My personal opinion is that you won't be happy.
Two growing boys aren't going to fit well on the sofa and dinette, and it will get worse as they grow. The dinette is not very large. My son had to sleep on the dinette in our popup and by the time he was 14, he wasn't a happy camper.
If I were you, I'd stick with the 2509S or look at the 2504S, both with real bunks. If you ever end up with a friend coming along (or cousin, maybe), the U-dinette is much better suited to sleeping the extra person, as it's much larger.
1988 Coleman Sequoia - popup (1987-2009) - outlasted 3 Dodge Grand Caravans!
2012 Roo19 - hybrid (2012-2015)
2016 Mini Lite 2503S - tt (2015 - ???)
2011 Traverse LT, 3.6L, FWD
2009 Silverado 1500 Ext Cab, 5.3L, 4x4, 3.73
2016 Silverado 2500HD Dbl Cab, 6.0L 4x4, 4.10