Pretty comparable boards there, both are good rides.
I haven't rode the Jamie Lynn Phoenix, but I have rode quite a few Libs... TRS 157 (c2-btx), T-Rice 157 (c2-btx), Banana 156 (btx), and Street 157 (btx). I had a Rome Agent Rocker 157 last year (loved it).
Personally I'd prefer the Rome (more durable, more pop & lively, everyone doesn't have one)
I do mainly freeriding so I can't comment on either of those boards performance in the park.