The old bikes have been using Cyclons for decades and I have never had a problem wht them.
They are Gel cells
However considering all of the Adsorbent Glass Mat batteries
that are Pressure Valve Regulated there is really no need for Gels any more.
You need AGM to support the grid plates with are about 20% the weight of the original batteries
so subject to mechanical failure.
The PVR prevents the batter gassing so they don't go POP any more & warm your legs.
Cyclons are virtually indistructable because the plates are rolled up like foil capacitor so they can take all of the vibes our bike put out but down here the distributor has a taste for fine wine & loose women which he finances through excessive pricing.