The "block value" it is not the main fact to consider. When you connect to a node p2pool the most important data to consider are:
1 - Latency or Ping (higher increase reject share = minor "gains")
2 - Node Efficiency and miner efficiency
optional:
3 - Know the owner of the node (He is concerned only gain or important to him is the health of bitcoin? Who is reflected with my ideas?)
4 - If the three above are similar between two nodes, you can view as a parameter "block value" to guide your choice...
..but....but....
The "block value" it could be higher, but contain fewer transactions with low (or 0) fees...but a "low block value" of one node "might also" contain many more transactions with low fees respect to a node with high block value.....better "high block value" with 100 transactions or "low block value" with 500 transactions? ...and here we return to the point 3
(is an example might also a node with "high block value" it contains more transactions rispect another node..all depends on how you configure bitcoin....on my nodes accept transactions with low (or 0) fees but this leads to fill the memory and it is perhaps this that reduces the block value on my nodes..
Example on my nodes with 2 different configuration:
1 - Total block value: 25.131898 BTC including 518 transactions
2 - Total block value: 25.181653 BTC including 466 transactions
If you are interested in the gain go to option 2 ...whether your interest is the bitcoin go to option 1....
ps: google translate