im currently running a tetratec ex1200 on my 300l. I have the spraybar at one end which creates good circulation around the tank (you can see this if you watch small particles floating around). However, i also have a nano 600lph powerhead at the opposite end shooting towards the gravel to help circulation and you can definitely notice the improvement.
Obviously my experience is with a 50% bigger tank but tbh an extra pump is only Â£35 or so and would produce similar flow without the cost (and maintenance) of another filter.
However, it is entirely personal preference and people like to have an extra filter running in case something goes wrong.
My first Tetratec 1200 leaked all over the floor while I was a work and the replacement (Tetra support is first class) was sold on Ebay. That said, flow from it was excellent if a little noisy.
But I do have a 200l tank. My Eheim 2028 turns over 800lph real flow (rated 1050). It is more than enough for filtration but not enough for flow. I've added a 400lph internal filter for 6x real turnover (but 8x rated turnover ) so although the Tetratec is noticeably more flow, if you plant heavily you will most likely find yourself adding a powerhead for extra circulation. JamesC also has a 200l tank and he uses a 2028 and a powerhead also.
When my plants get going more I will most likely switch the internal for a Koralia Nano for 800lph taking me to 8x real turnvover.
So my advice is plan to use a powerhead or a Koralia and get a filter around the 1000lph mark OR just aim for a filter around the 1600+ mark (Eheim 2076/8 or new JBL for example).