used to have the tennis tutor plus and now have a lobster elite 3. the only benefit of the tennis tutor is the size, but the lobster is better in every other way. it's easier to transport, more robust because the hopper isn't a thin plastic flap, and holds more balls. performance is pretty similar from my end.i also carry my lobster from a second floor apt to my car and then to the courts. it's easier to carry the lobster imo because the weight distribution is a little better.
i would suggest looking at CL first. if you can score a decent deal on a used one, you'll at worst break even when you decide to sell.
This the shape and weight of the Lobster is the best for transport, having tried the tennis tutor plus (too boxy, wheels too small to roll around, had to stoop over to use the handle, tennis tutor support is the best of any company imo).
Spinfire 2 (older model) was just way heavy with the battery, very tough to get in and out of the car, wider than the lobster. Very heavy and too big for a 13 year old and 10 year old to carry. My friend has the newer model and has to have the external battery option, so he has to carry the ball machine, basket of balls, racket bag and the external battery.
Have a Lobster and it's been flawless, the only thing I had to do was change the battery (on this model only took 5 min). It's only 29 lbs without the battery but it's a very manageable 42 lbs with battery and the porportions are good to wrap your arms around to carry and to roll to the courts.
