Other than the wear & tear, do you like the bike? Are you still using original tires, cluster, chain (I hope not!)? They may be past due replacement at 4,000 miles. I'd look into new tires (and tubes and rim strips), replace the chain and cogs, have a knowledgeable mechanic check the chainrings for excessive wear (assuming worn chain and cogs) and make sure the wheels are true and the hub bearings are OK before replacing an entire bike. As well as general lube and adjustments, maybe new cables and housings. Even if you paid a shop to do everything, and replaced the front and rear wheels as well (which may be a great value, depending on the quality of the originals), it will cost less than a new bike. If the flat handlebar isn't comfortable on longer rides, consider adding clip-on "jammer" bars (like aero bars), or convert to drop bars. A different saddle might help, too.

Now if the Sirrus Comp isn't right for you, happy shopping. The Sirrus Pro looks like just a fancier Comp, so if the flat handlebar style isn't working for you, the Pro will not fix that problem. The Tricross series are cyclecross bikes, intended for recreational or competitive riding over a mix of pavement, packed trails, grass, mud, and carrying over obstacles. Many people do use 'cross bikes as commuters. If you are riding entirely on pavement and don't need wider tires for bad weather commuting, a pure road bike my be a better choice for comfortable century rides.

The other factor is your commuting. 7 miles round-trip per day, almost anything will do and you can carry your gear in a backpack. 35 miles per day and a bike that can mount a rack and panniers (or a large enough Carradice saddle bag)may be better (that would be what I would do). A road bike set up for commuting (can take wider tires, fenders, rack) but able to do long distances comfortably may be the best. Can't suggest a specific model, but see what your local shops sell. Good luck!