I have only had this antenna for 2 weeks and find it to be great on all bands, no radias required, easy to erect and tune.

The GP 2500 antenna
The quality of the antenna is what I call good I wouldn't say it was the best but for a budget antenna it's probably on the top end standing at 7.5 in height ideal for a person with a small garden. performance the antenna performed well between 20 meters and 10 meters 7 meters was okay but not the best 80 meters founded a little difficult to make contacts this is in my opinion running 100 Watts through a comet cat three hundred ATU . Inner compromised antenna the performance is fair to good you could get better by having a mono bander but then that does not give you the scope that most amateurs want. The Istanbul you are performance without ATU is as follows
3.700 1to 1.9 swr
7.100 1 to 1.2 swr
14.112 1 to 1.5 swr
18.112 1 to 1.5 swr
21.200 1.to 1.8 swr
24.941 1.to 1.9 swr
28,500 1 to 1.8 swr
50.112 1 to 2.4 swr
When the Comet tuner with a corrected swr on all bands, the tuner gives the good swr on all workable bands

I use this antenna for a month and i like it but 250 watts is not enough. it should be 1 kilowatt.

Great aerial to put together and erect. Just make sure as others have stated that you use good quality self amalgamating tape on all joints and the base of the vertical where it joins onto the coil. I've always done this with my antennas anyway so i haven't had any leakage problems with water. Very good reports into Eastern Europe and Malta so far. Most antennas are a compromise in some form or other but if you are stuck for space and you want a multi-band HF aerial that works, i would definitely recommend you try this!

Fantastic antenna when new but the coil fills with water and i have 2 of them both same problem i have had to drill drainage holes the water runs down the element on to the top of the coil then weeps down the threads at the top of the coil and fills the coil with water this is some thing that needs sorting as it spoils a otherwise good antenna .

Good antenna one major weakness is where the antenna element connects to the bracket and coil in wind it causes the top of the coil to flex and allows water in to the coil i have has this problem with both of these antennas o have cure is to put brackets between the top of the coil and the top mount on the bracket . Needs to be reworked at the factory to sort this problem as i know 3 others local had the same problem .

I bought this antenna as I had S5 noise level . With this antenna the noise level is down to S1.
I can hear signals that are about 3 S points down from the main antenna

Great reception.. Picking up signals from North America, South America. Europe, Africa. Haven't made a contact yet, but then I'm only transmitting 5W. One negative to mention is wind. When It was first up, I got frightened by the amount it was whipping, so it came down again and I rigged up some guywires (Nylon rope) from half way up its 7.13meter length, this has substantially reduced the whipping. I must admit, I do live in a very windy area.

I am about to buy another as this stick gives excellent reception.
On WSPR I am often the only Brit hearing the Oz and NZ stations.
Not transmitted yet but why would it be bad.

M0PJK