I'm one who is extremely partial to the 109F.... Why? Back when the revised 109s were introduced, and the flight model revised, I started flying the 109F a great deal. I remember how I introduced many to the uber flaps. One well known and highly respected player (and very capable dueler) met me in the TA to explore the capability of the 109F. He flew just about everything in the inventory against my 109F. Zeros, Spits, LaLas, Niki, F4Us and the like. The 109F won every duel. Of course, you fly it differently depending upon the opposing fighter.
It's not like the 109F hasn't weaknesses. It does. However, those weaknesses can be avoided. For example, every 109 has torque issues at low speed. This is magnified if you have the flaps out. At high AoA, very low speed, 109s simply will not roll to the right with the throttle up (even with full right rudder)... You can pull off power, but you risk a stall. I learned that it is invariably better to simply roll left and adjust as required.
Bighorn2 (using one of his many aliases), and I slugged it out with me in a 109G2 and him in an La-7. The 109G2 was better overall. However, only as long as I avoided the torque issues by sticking to my dictum of "always go left". The reason is that going right takes too much time or depletes E by chopping power. Without exception, going left was quicker and left me in a better position to fight. If I had broken with my rule, the La-7 would have gained an advantage. This is a general rule and it applies to every 109, including the K model.
All 109s suffer from control stiffness at very high speeds. Keep it below 500 mph. Use trim to get them out of high speed dives if necessary. Visibility is marginal... Don't load external guns (gondolas) unless you plan to attack bombers and not have to deal with fighters. Utilize the excellent climb and acceleration. 30mm cannon will kill any fighter with one hit... If you're new to 109s, avoid the 30mm if possible until you have some time in the 109s. The 30mm ballistics are poor and it takes much practice to develop good accuracy. On the other hand, the 20mm is more than adequate if you can get several hits.
All in all, any model of 109 will be fun and lethal....
190s... I fly them a bit in the MA. I duel in them often enough to feel confident in the aircraft. Ultimately, 190s depend upon maintaining E, either in the form of speed or altitude that can be quickly converted. Do not expect to out turn anything short of a bomber, and some bombers can turn inside any 190 (Boston and A-20G being two). This is a fighter that thrives on being flown fast and in the vertical. It can change lift vectors instantaneously, which is beneficial in getting a pursuing enemy out of sync... Don't bother with a flat scissors. Why? Because any pursuing pilot worth a hoot will simply high yo-yo and shoot off your winkie post-haste. Remember, the way to avoid an overshoot is to change directions. Going vertical is a great way to take advantage of a 190 driver trying to force an overshoot with a flat scissors. He's burned off his E and you're sitting above him with every advantage. 190s are well armed and well armored... They can give and take a beating.