As far as spending money on this unit. As I stated before the advantages are all the bulbs and t5 ballast contained in 1 package. The mh reflectors in the unit are designed to spread as opposed to focus the light downward as it is in the larger pendant style ones. Not significantly, but enough to make a difference. I would not use on of those parallel style reflectors without T5 supplementation (personal preference. I'm sure one would not have any problems). The unit has t5 supplementation built in so its not a big deal either way. The importance for knowing this might be to effect aquascaping layout to take best advantage of the light available.
a quick reference on spectral light spread
parallel reflector
pendant style ( I looked for the lumenmax elite as thats what I use)
These charts are not great side by side comparisons as they are taken from different studies using different depths, ballasts, and bulbs with the 1st using a 10k the 2nd a 14k, both by ushio. They do however give a good impression of spread distribution. Both reflectors will provide sufficient intensity.
For those interested, there are tests on various reflectors done in the mid 2000s (google sanjay joshi mh reflectors, and look for parallel reflector data)
What do you get for spending over a grand? A nice shell and three sockets and a t5 ballasts?
This is essentially correct. there is nothing wrong with that but its an accurate statement. Though we forgot about reflectors.
Ask anyone who has ran Geismann for their opinion and see if you get any negative view on it
I used a giesmann single MH unit over a smaller tank for a few years ( maybe 3) back in the mid 2000s over a 40b. The unit was fine mechanically, it did start to rust slightly on the hanging fixtures that came with it (the ones that slid into the channel lock on the top of the unit) and the allen screws that held the side panel and glass shield on. It never stopped working and I sold it in good working order.
No different if I spent 3200 on 4 radion pros
You spent roughly $1200 to$1300 thats a huge difference.
4 radion g4 pros are insufficient on a 180 considering spread. Unless one can mount them 2 feet or more above the tank.
Sanjay Joshi is up to 10 over his 7 foot tank.