Thats why open discussion is healthy, were all here to learn.
My view on the 3300 is it will do well at this time of year, assuming when you say you have "16 panels" they are 250w panels, but you could lose out in the summer versus the bigger inverters. I read on here the other day in an ideal world you would have two inverters - a smaller one for the winter and a larger one for the summer, and the reason being inverters like to be worked hard at there upper limit, so in winter when its dull and the sun is low its ideal to have a smaller inverter on the end of a lot of panels, and in summer when the panels are beating out high output the smaller inverters are going to struggle to keep up - its like driving down the motorway in 4th.
Im not sure the price difference comes into much in the scheme of things when choosing between different models of inverters, and i feel design is more important - once someone has made up there minds to have solar its about getting the best out of the roof space for that given situation.
Yes - and if the panels aren't at an optimal facing (South) and an optimal angle to face the mid-summer, mid-day sun straight-on (about 25 degrees, if I remember correctly) then they won't ever reach maximum potential.
However, although South and about 25 degrees harvests the most in the middle of summer, it is by no means a good angle for other seasons due to the sun being lower in the sky and therefore no longer able to face the panels straight-on. For winter harvesting of sunlight, the optimal angle is quite steep.
Bearing in mind a combination of the direction in which the panels face, plus the angle at which they are mounted, plus the time of year, plus the capability of the inverter.
With East or West facing panel arrays, it should not be a problem to somewhat "oversize" the panel array because of the inability of the panels to ever work at more than about three-quarters maximum output.
I have 3.75kWp on a 3.6kW inverter, facing SouthEast at 40 degrees. If I could have made 4kWp fit nicely/look good on my roof, I would have preferred a 4kWp array and keep the same 3.6kW inverter because I doubt that my array can ever reach maximum potential.
Note that when I talk about maximum potential, we in the UK need to be realistic and appreciate that most of us have sub-optimal options for panel positioning, but we can still get a reasonable output.