BearShare was certainly an advanced program for its time compared to the others. I guess it depends upon what aspect you wish to make comparisons. All gnutella programs should get about the same search results. This can vary depending on the particular peers you are connected to and what peers and leafs they are connected to.

To my knowledge, BearShare did not introduce UPnP support until 5.2. Which suggests anybody using the BearShare 5.1 beta or earlier should forward a port in their router to prevent a router's NAT firewalling effect.

The later versions of gnutella clients added more up to date gnutella protocol. This includes for connectability. To my knowledge at least, GTK-Gnutella has the most advanced protocols. Even beyond what LimeWire or FrostWire had. I guess one reason is LW was somewhat predisposed to getting their totally rewritten version 5 up to scratch for useability. And did not even get around to returning many tools version 4 had. ie: they were trying to simplify the program for marketing appeal.
GTK-Gnutella and Phex might be worth trying at least if LW does not appeal. You can make your own comparisons.

BearShare 5 versions still use GWebcache host sites intended to help keep old gnutella versions running instead of the newer UDPHostCache sites. BearShare only uses its own kind of UDPHostCache for connecting with other BearShare hosts.

I might be wrong, but I have some doubts GTK-Gnutella connects to BearShare versions any more due to it lacking some of the later gnutella connection protocol. At least I've never seen them connect to any of my BearShares over the past 12 months. (I sometimes run up to 4 or 5 BS's at a time.)

You might even have some interest in trying one of the multi-network programs which includes G2.