I have a G0709 lathe and have been very happy with it. I've had it for over 3 years and have had zero issues with it.
The switches on the head stock were a little "spongier" than I'd like. They are merely screwed to the ~0.060" thick aluminum placard on the head stock. I backed up the thin aluminum with a 1/8" thick aluminum piece so the switches a rock solid.
Didn't like the cap screw for a carriage lock either. Ended up making a stainless steel replacement with a lever.
The oil fill cap on the head stock is fine, but it sets above the surface of the lathe. I put a 1/4" rubber mat on top and cut a hole to clear the plug. When I pull the back cover to access the quadrant, that end is unsupported, so ended up with a piece of 1/4" plywood on top with the rubber on top of that. Not a workmanship issue, just a preference of mine.
The back head stock cover attaches with a couple of thumb-nuts over studs. Not the most convenient way to access the quadrant to get to the ball oilers. A hinged cover would be nicer.
Personal preference of mine, but I don't like the clutch type adjustments on the cross feed and compound dials. I prefer a lock screw, so modified my cross feed dial when the taper attachment was installed to a conventional set up. Still need to do the compound. The problem I have with this method is you need to hold the crank in position as you turn the micrometer dial. Probably just my technique, but I end up moving the crank some while turning the micrometer dial. With a lock screw, the dial is free to spin so no issue with moving the crank.
Workmanship was fine on my lathe, no dings, dents, etc. as received. After leveling ran a test bar and was within 0.0004" over 8". All of the cranks and movements were smooth as received.
Pros: Like the universal gear box, can change between English and Metric threading without having to change gears on the quadrant. Can't tell you about the 1340, but I'm sure the info is available on line. The 1340 has a open QCGB so it'll be a little louder and you'll have oil on the drip pan. Not a big deal as 99.999% of old American iron works the same way.
G0709 comes with a BXA QCTP, 1340GT has a old 4-way turret.
G0709 has a D1-5 cam lock spindle, 1340GT is the more common D1-4.
G0709 speed range is 70 - 2000, 1340GT is 90 - 1600.
1340GT does have a better light than the G0709.
G0709 has a pull out chip pan, 1340GT does not.
G0709 comes with the stand, 3-jaw, 4-jaw and face plate. Drill chuck is not the best. I think the 1340GT comes with just the 3-jaw. 4-jaw is an accessory, don't know about the face plate.
I've never seen a Taiwanese lathe first hand so can't give you a 1 to 1 comparison. I have a Clausing 5418 lathe so will compare the G0709 to it. My Clausing just feels smoother than my G0709. Might be the gibs are looser, but it just moves easier. The carriage is geared differently, might be a higher range on the G0709 because of moving the extra weight as compared to the Clausing. I can push the carriage back/forth on the Clausing by hand, can't on the G0709 (not that this is a big deal).
I'm sure either lathe will serve you well.
Bruce
