We dove Makos for years and I liked them well enough at the time. At 53 pounds they are heavy. The hulls are also fragile and prone to leaks, especially when hauled on and off boats. Sand will get past the first o-ring and eat at the soft plastic sealing surfaces and you'll be looking for a replacement mid body or nose cone fairly soon.
Battery life is 45-60 minutes depending on prop pitch and batteries are time consuming to change ands time consuming to recharge.. Also, if you run one hard at max pitch continuously and it's one of the higher RPM motor winds, you'll overheat the battery and the case will sag. You'll then discover the scooter won't seal on the next dive and you'll be dealing with a significant leak or flood. Wiring can also get hot in them on the faster motors. Motor winds varied from around 750 rpm on average to as low as 600 rpm in production Makos and you'll find some of the rebuilt Makos will have 900 rpm or 1000 rpm motors in them.
Props, hubs and a fair amount of parts are still available for Oceanic motor and cowl based scooters through Dive Xtras, but many of the other Mako specific parts (tails, mid bodies, nose cones, etc) are only available as used parts cannibalized from other Makos.
The Apollo based scooters share many of the same faults as the Mako, just in a slightly smaller package and with the advantage that they are still in production. But at $3800 for a new one, you can get a lot more DPV for a lot less money.
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The Dive Xtras BlackTip is 22.2 pounds weighted for fresh water and 22.8 pounds in sea water. It'll offer Mako run times but with a lot more thrust and speed, and it'll do it on 9 Ah power tool batteries. A pair of Waitley 9Ah batteries will cost you around $140, and with 2 sets and $280 invested you'll be set for any 2 tank NC dive, wreck or meg ledge.
The hull is a tube and much more durable. I'll take knocks and dings in stride that would ruin the hull or sealing surfaces on Mako or Apollo and it's depth rated to 300 feet, with a 100% margin over it's 600 foot crush depth.
The BlackTip is also only $1,499.95. I can discount that by 10% and throw in a cradle, and I'll have another one in stock on Monday.
I'm in Winterville NC. Send me a PM or message me on Facebook and we can arrange a demo, either in open water or in a pool.
Karst Scuba
As an aside, etiquette matters on a meg ledge as some boat captains are not real scooter friendly. Divers using a scooter to dig can screw up the viz for other divers. As you have noted, digging with a scooter can cause other divers to feel disappointed when they bring up a whole bag of teeth rather than just a few and if taken to extreme that perception of not doing well with just a few teeth can cut into the boat's repeat business.
Do your digging down current, try not to show off too much, and don't be a burden on the boat crew. A 22 pound BlackTip will be much better received than 53 pound Mako when you ask a mate to lift it aboard.