Note: Balboa 20 was designed by Lyle Hess who has (he's passed away) a devoted following. His designs are known to be safe and stout though a bit slow. Look over a Balboa 20 or Ensenada 20 then go look at a San Juan 21... the Hess boat will seem like a Jeep while the SJ seems like a 1990 Hyundai.
Not a good comparison, given the reliability ratings
of Jeep v. Hyundai.
Yah, the SJ21 isn't exactly built like a tank. But it will lap a Balboa20 around the buoys. Twice.
The problem with sailing a boat that's leaking a gallon per hour around the keel box ... is that you fall off the back of one wave, and suddenly you are taking on twenty gallons a minute and your little daysail just got a whole bunch
more interesting. You can drown on Lake Winnebago as well as in the south Atlantic.
I like the B/E/RK20, but it is as old, beat-up, and expensive to keep in sailing trim as any other 35 yr old plastic boat. For my money, I wanted a boat that at least had good sailing qualities. If you can get the B20 for a song and are willing to put 100 hours into it, then by all means. You'll end up with a sluggish boat worth $1500 resale. I personally know a nice, devoted, and highly-skilled woman with an E20 who bought the boat, began working on the keel
(leaks around the box, pitted cast iron), and has been off the water for several years
as she tears into the hull -- at each step finding another major problem that needs addressing before the boat can be safely reassembled & splashed again. The endless repairs that come w/ sailboat ownership are a lot easier to cope with if you can sail in between them. The keel/trunk of the B/E/RK is a known problem area and has allegedly resulted in lost keels; it should be addressed.