I'd be very much interested in what Mexico Wanderer thinks about your expectations, and if they need to be adjusted on the number of recharge cycles. Around me, I see 500 to 650 cycles on a lead acid Trojan T-1275, before they get 86'd out of the golf cart as being used up and unsuitable for that kind of heavy current draw from electric motors, starting and stopping.
Of course, for my purposes, drawing 10 amps max, mostly 4-5 or 6 if the TV is running (rarely), and a 24 amp draw total from parasitic loss over 24 hours, I think I am doing OK.
I think a new Trojan T-1275, if it fit, and if you kept it watered and topped off on charge, or a pair of 6V GC-2's wired in series from Costco or Sam's Club, would be the next good experiment, if you want to water batteries, and use your specific gravity meter to take a peek from time to time.