I'm doing my research for a roadie too currently. Have been pounding my 2002 steel 18 speed MTB hardtail and a newer and lighter 2016 alloy flat bar hybrid 21 speeder.
Looking at Merida, Scott, Giant, and Canondale mainly. Will also check out some specific models from Ridley, Trek and Specialized.
Not looking at a race or aero frame, but something that is more endurance inclined. More upright, for longer hours in the saddle.
Do share which bikes you are looking at. Photos would be great.
Basically buy the lightest frame you can afford. The components can be upgraded once they wear out.
A compact crank if a two chain ring one (50-34) or even better a triple chain ring crank would give you both speed as well as help up the mountains.
Getting the correct size is the most important thing. There are tons of calculators and tables online. If between sizes, the rule of thumb is go smaller if you want to ride aggressive, for speed. Go for the larger frame if you want more comfort at the cost of performance.
The choices would be priced upward depending on the groupset on the bike. Usually Shimano, sometimes SRAM.
This is the pecking order in terms of slickness and preciseness and speed of shifting as well as lower weight -
Tourney (7) < Claris (8) < Sora (9) < Tiagra (10) < 105 (11) < Ultegra (11) < DuraAce (11; mechanical and electronic)
Tiagra is the entry level for serious roadies. Though Sora is not bad for beginners or those who will not be cycling much. Or competitively.
I would personally not bother with Claris or Tourney. Too basic.
Till Claris you should get wide spaced 11-32 cassette for the rear. Tourney will have 11-28 only. Tough in climbs.
Hope this helps. Fire away if you have any questions.
@Rafael
Cheers, Doc