I had a very similar experience: Platinum staying for 2 days (extended to 3 due to hurricane...) last week staying here as it was close to my client.

Upgrade to suite with 1.5 baths, not a great view but overall a good space with a very large bathroom and bath and separate lounge area. This was a blessing considering I spent 2 days pretty much locked in the hotel.

Lounge (always a bonus for a Courtyard and pretty rare) had a good selection of free alcohol (local and international beer, plenty of ok wine), plus nibbles and a "rice chef" in the evening (you chose your own meat and veg for him to fry with a sauce). Breakfast was served in the hotel restaurant with an egg chef, steamed vegetables and then a good American selection (bacon, sausage, bakery items) plus some vegetarian Chinese curry type meals. Staff were also polite and friendly.

There was also an attached mall with a very good selection of restaurants (very much recommended if you want to eat nearby, in preference to the hotel)

However, to be clear it is still a Courtyard and having stayed at the Marriott across town it wasn't in the same league, though not too dissimilar. My "complaints" (being unfair as this is a Courtyard after all), but comparing to in general Marriott hotels as it really wasn't super cheap) were food related. Bearing in mind most of Taipei has great food: The hot lounge selection except for the rice chef was a bit basic and didn't change each day. There were two soups and some steamed vegetables. In addition the restaurant breakfast was missing dim sum and beans, which you'd normally see around Asia. In general the hotel is more tuned to an Asian palette. My room service meal was about the same Marriott pricing (i.e. expensive) but the menu wasn't really very large - more annoyingly it didn't appear to have any Taiwanese foods - more European and other classic Asian dishes (Singapore Noodles, Nasi Goreng).

If coming back to the city I'd still be tempted by the Marriott if it wasn't that much more expensive. Neither hotel has a great location for getting into town, suspect the Courtyard is actually better placed due to the high speed rail direct to Taipei station.